IECO Dual Weber manifold (IECO is no longer in business)
IECO Valves--actually modified 305 valves--valves from a 173 V6
might be better
Offenhauser aluminum intake
Crane and Crower cams
Headers by Ed
Edelbrock intake with Holley carb
Kevin (SoloII_74) adds: "[The intake] could be duplicated without a whole
lot of trouble, since it is just sheet metal. You should be able to go
faster by increasing your compression (by milling the head & block, or
custom pistons) to about 9-9.5:1 (something I can't do), changing the cam (I
could not because of the rules), adding a used 4 bbl intake, or fabricating
a dual weber intake, and getting a header from Ed (expensive, but worth it).
With a little work, you should be able to make it to around 200 hp.
Unfortunately, the 4bbl intakes are hard to come by, and cams are getting
rarer too. My '74 only weighs in at 2200 lbs. with me in the car, and your
'77 wagon most likely weighs quite a bit more than that, so your 1/4 mile
times would tend to be slower than that, unless you can get the weight
Tom (tbecker_525) says: "The Crower cam I have is Part #07356, Grind No.
286-F, "COMPU-PRO". I have the spec sheet.
Intake: Duration - 286 degrees, lift 477, clearance hot 022
Exhaust: Duration 294 degrees, lift 490, clearance hot 024
At .050" tappet lift - Intake opens 16 BTDC, closes 48ABDC; Exhaust opens 60
BBDC, closes 12 ATDC
Lobe seperation - 110 degrees
Duration at .050"
Intake 224 degrees, lift .477
Exhaust 253 degrees, lift .490
Best I can tell it's rather radical... I'm still looking to see the year
of manufacture to determine whether it's hydraulic or not."
Randy (monzamiler) adds:
"Jeff, The last time I needed bigger valves for a Vega engine I got mine
from Donovan Engineering in CA. They cost $35.00 ea. and were well worth the
money. I ordered mine with cut down stems on the intake. Yes you can cut
down a V-8 valve but you will need to use a lash cap. The only lash caps I
found only left .002 side clearance which I thought was a little to close to
"My 140 we built for a 3/8 mile dirt track includes Buick V6 pistons, Ford
small block valves, Lunati cam, Quarter Master 12lbs clutch, Isky valve
springs, and some other little tricks. The combination yields a dyno
150hp at 7,000rpm!. And they all told me it would never work. They're still
scratching their heads."
About the clutch, he adds:
"The clutch is a 2-disk self contained assy. It is designed for a V8, but
will bolt directly to the back of your crank. You run a flex plate in place
of your fly wheel. The assy is 7-1/4" dia. Its not much for taking off, but
frees up big top end."
Install a 4 core radiator or have the original radiator re-cored. For a drop
in replacement, Griffin makes 6-577AV-BAX (with trans cooler) and 6-577AV-XXX
(without transcooler). These cost around $500. For a cheaper "generic" radiator,
try Griffin part #55241 or #25241 but be prepared to do some work to make it fit
the Griffin # 25241. This rad has the following specs:
27 1/2" wide
15 1/2" tall
3" thick tanks
2 1/4" thick core
23" wide core
2 rows 1"
Griffin # 55241 same as above except for two 1 1/2" tubes.
Griffin # 25241 is $181.95 and Griffin # 55241 is $281.95.
These rads have the lower outlet angled up on the passenger side. You need to
make some room on the bottom at each side for the tanks. The rad sits right on
the lower part of the stock rad cradle. I have this rad and a long water pump
and still have room for a good fan."
turbo 350 ratio
Three speed Turbo-Hydro matic automatic optional on all
Gear ratios: 1)2.52:1 2)1.52:1 3)1.00:1 R)1.94:1
The gear ratios listed are for 1976 (Vega) and 1978 (Monza). The ratios
change year to year even for the same transmission/engine combination. You can
find complete data in the Standard Catalog of American Cars. Or, just check your
rear (see question 3.6).
2.92:1 with three or four-speed manual
2.93:1 with five-speed manual
2.92:1 or 3.42:1 with automatic
4.10:1 in Cosworth
2.73:1 L4 with three- or four-speed manual or automatic
3.23:1 L4 with five-speed manual
2.56:1 V6 with three- or four-speed manual
2.73:1 V6 with five-speed manual or automatic
3.08:1 V8 with four-speed manual
2.29:1 V8 with automatic
If you have your build sheet, look for a "G" option code and compare it to
the option codes list--this will tell you what ratio is supposed to be in the
John B (vegadad) has provided information about identifying a rear end
To get a good guess, you can jack up the rear of the car (BOTH wheels). Mark
one tire and mark the driveshaft. Turn the driveshaft until that tire makes one
revolution. While you're doing this, count the revolutions of the driveshaft.
This number of revolutions is your ratio. Your ratio is not likely a whole
number so you'll have to estimate how much of a revolution the driveshaft makes
as the tire finishes its rotation. The number of revolutions is the ratio.
To be completely sure, open up the rear. Count the teeth on the pinion and on
the ring gear. The number of ring teeth divided by the number of pinion teeth is
the gear ratio. For example, a 1980 Monza 4cyl automatic has 41 teeth on the
ring gear and 15 teeth on the pinion gear. 41/15 = 2.73333333, for a 2.73:1
Positraction rears are supposed to have a tag reminding you to use a special
GM friction modifier when you change the fluid. This tag may come off.
If the tag is missing, jack up the rear of the vehicle and spin a rear wheel.
If the other one spins the same way, you have Positraction (or a locker or spool
or something!). If it spins the opposite way, you have an open (regular) rear.
If it doesn't spin at all, you have a problem (locked up brake, broken axle,
Do a burnout. If you have two patches of rubber, it probably works! :)
Or, jack up one rear wheel, leaving the other on the ground--make sure the
car is in neutral and the parking brake is OFF. Next, chock the front wheels so
that the car WILL NOT move. Then, using a torque wrench, attempt to turn the
raised rear wheel. At some torque value ("breakaway torque"), the wheel will
start to turn. If this value is above 60-70 ft*lbs then you're OK. Otherwise,
try changing your fluid (see question 3.9). If that still doesn't help, it's
For street use: 75W90 gear oil plus GM's friction modifier. The friction
modifier makes the lube more slippery. This allows the clutches to let go more
easily, and last longer. It also keeps the rear quieter. (Note: Redline's 75W90
doesn't require the GM modifier, they claim.)
For race use: straight 75W90 gear oil with no GM additive. The posi will grab
better but make lots of noise and possibly not last as long. (Note: Redline
recommends their 75W90NS in this case, since their 75W90 is "slippery" enough to
act as if it has the additive).
Positraction is kind of like a part-time locker for your rear end. When
you're going in a straight line, the two rear axle shafts are connected together
by a mechanism (cone, clutches, or gears, depending on the type) in the carrier.
This aids traction greatly. When you make a turn and one wheel needs to spin
faster than another, it can because the mechanism gradually lets go and allows
the axle shafts to spin at different rates. However, having the partial-locking
action helps in turns too because without it, the inside rear wheel would spin,
keeping you from accelerating as fast. If you have an open rear end, the rear
wheel with the least traction will get the most power, leaving you to spin the
wheel uselessly in low-traction situations. If you have a locked rear end,
you'll scrub your tires around turns. This is OK for drag-strip only cars but
not a good idea for the street.
To add Positraction:
Locate a Positraction carrier, preferrably from an H-body, or a similar
locking carrier from an aftermarket company. Make sure you get the right
series carrier: 2 series for 2.XX gears and 3.XX up to 3.08, and 3 series
for 3.23 up to 4.10.
Drain your differential and pull the axle shafts.
Measure backlash with a dial indicator.
Remove the carrier and ring gear. Note preload.
Move the ring gear to the Positraction carrier.
Reinstall the carrier in the housing.
Use shims on either side of the carrier to set the same backlash you
measured earlier. Put the same preload on the carrier.
Refill the housing with gear oil that is designed for positract (see
The main problem is that, in the differential case, the hole for the pinion
bearing is smaller in the H-body differential than in other GM 10-bolt
differentials. You can either get a machine shop to enlarge this hole or use a
special pinion bearing and race.
So, the list is:
Enlarge pinion hole in differential and use S-10 bearing, race, and seal
Use these non-factory parts:
Timkin bearing #16143,
Timkin bearing race #16283, and
National seal #8610.
Tony (tony63underwood) says that Timkin bearing 16143
crossreferences to BRG bearing part # BR42687 (this
crossreference has been reported to be wrong--use at your own risk)
and the race 16283 crosses to BR16283.
7.5" gear set with pinion
new carrier if the new gears won't fit your current carrier (see 3.10)
S-10 rear end yoke
"Combination" U-joint (Dana #5-3022X) to mate the S-10 yoke with your
While you're in there, you can upgrade to a new or different posi carrier by
getting a 26-spline carrier of the right series for your gears (see question
NOTE: Installing new gears requires setting the proper pinion depth and
carrier position. Doing this wrong will destroy your gears. Even the most
die-hard shadetree mechanics leave this to a professional. If you want to try it
anyway, this is the basic procedure and tips from Robert (twelve_second_vega):
"When you pull the carrier, mark the shims on the side of each bearing. They are
cast iron and must be handled with care. Put a new crush sleeve on the pinion
and install it in your 7.5" housing. Set the preload (about 10 inch pounds with
used bearings) and set the carrier in place. Gently tap the shims you took out
into place with a PLASTIC hammer and torque the caps. Only 1 gearset I installed
needed to be reset. 99% of the time, you can just throw them in and go. If the
backlash is off (.005" - .008" with used gears) you will need different shims.
Subtract the amount you need (in backlash reduction) from the right shim to move
the ring gear deeper into the pinion. BE SURE to add this SAME AMOUNT to the
opposite shim. You MUST maintain the preload on the side bearings. When properly
set-up, you will have to pry the carrier out of the housing and putting shims
back in should not be easy either."
Bob (botizan) adds this tip:
"When installing F-body or other 7.5" gears in your H-body car, you can keep the
H-body U-joint by using the yoke from a 76-79 X-body car
Yes, but you'll need to transfer (cut then weld) the brackets for the coil
spring suspension since the S-10 uses leaf springs. Also, you'll need to figure
out how to mount the torque arm if you have one, or revert to the previous
4-link rear suspension.
Lee Abel of Abel Performance (Phantom402) gives more details:
"Found out a neat thing today the springs on an S-10 are exactly the same width
as the rear control arm mounts for my 75 2+2 factory v8, so I'm gonna cut down
the springs, clamp the leafs together, and bolt it in. Add the spring mounts and
panhard bar and its done except the brake line... no problem, tack weld piece of
metal to frame some where convienent and hook up s-10 hose. BTW some later 80's
earlier 90's S-10's came with 8.5 10 bolts so all ya gotta do is up grade to a
2wd vesion an boom ya got a rear end that is about as strong as a 12 bolt after
a lock right, moser axles, "c" clip eliminators, summit pre load cover, and
mobil 1 gear oil. If ya find a f-body from 70's or early 80's you can swap the
Yes, but first you'll need one from an '82 or newer car with the torque arm
suspension. Then you'll need to have it narrowed if you're not using the wide
IMSA body panels. Make sure the brackets end up in the right place! Finally
you'll need to modify the torque arm mounting area.
Roger (monza_madness) gives more details: "The stock F-body (3rd gen
1982-1992) rearend will fit an IMSA panel Monza using 10" wide wheels with 4"
back spacing. No shortening required, just relocating the H-body spring perches
and H-body control arm mounts. Widen the H-body control arm to fit the
differential housing. The front differential mounting holes have to be redrilled
in the control arm. The control arm upper and lower ridges have to be notched,
and control arm has to be pulled to a 90 degree angle to the rearend and the
ridges have to be rewelded. Careful not to use the German made firebird rearend,
identified by finned aluminum brake calipers, as this is a light duty rearend.
Also can be identified by the 9 bolt differential cover.
"When moving the spring perches and control arm mounts, I used the
differential case as a reference point. Then I double checked the distances
between the spring perches to guarantee proper positioning. I used an angle
gauge mounted to the pinion bolt holes, set at 5 degrees down, then used the
level to set the perches and control arms. For the pan hard bar mount, I
installed the rearend with spring perches and control arms tacked in place into
the car (monza). With control arms and springs and torque arm in place, I lifted
the full weight of the car with the rearend. The mount, with the pan hard bar
attached, was placed on the rearend centered with the marks that were measured
off the old rearend. Check that the wheels are centered in the body, then tack
the pan hard mount into place. Then I removed the rearend and finished welding
everything into place."
If you're hooking up well (for example, using slicks and getting low 60'
times in the 1/4 mile), people seem to agree on 300 rwhp. After that, start
looking at aftermarket 12 bolt or 9" or similar rears. Don't get an S-10 rear
thinking it will be stronger because it probably won't be. Also, people with
Camaros making just over this much power break rear ends, so don't look too hard
in that direction either. If you're making much more than 300 rwhp, you deserve
a custom rear anyway. :) Don Hardy 12-bolts seem to be popular.
If you're not hooking up, then it almost doesn't matter how much HP you drive
through the rear end because you're just spinning the tires anyway!
Over the manufacturing life Of the H-body, several Gear ratios were offered
in either a 6.5" or 7.5" ring gear configuration. From 1971 through 1975 all of
the rear axles were equipped with the weaker 6.5" ring gear. In 1976 and 77 some
of the H-Bodied cars were equipped with either the 6.5" or 7.5" ring gear.
H-bodied cars from 1978 and later all are equipped with the 7.5 ring gear
The identifying code is either located on a metal tag attached to a cover
bolt or is stamped on the right front side axle tube about 3 inches outboard of
the carrier, approximately 30 to 45 degrees above the horizontal.
FIRST 3 LETTERS ARE THE MINIMUM REQUIREMENT FOR IDENTO-PLATE
D = DAY SHIFT
N = NIGHT SHIFT
LIMITED SLIP ID
W = BORG WARNER
E = EATON
O = OLDS
NOTE: 1978 MODELS THE FOURTH CHARACTER
INDICATES MODEL YEAR
FIFTH THROUGH SEVENTH, JULIAN DATE, THE EIGHTH CHARACTER, SHIFT CODE.
B = BUICK
G = CHEVROLET GEAR AND AXLE
O = OLDSMOBILE
C = CHEVROLET BUFFALO
P = PONTIAC
K = GM OF CANADA, ST. CATHERINES (MCKINNON)
M = PONTIAC CANADA
W = CHEVROLET WARREN
The build sheet is the factory's listing of what options they put on your
car. It is "hidden" somewhere in your car during its construction.
For Vegas, try under the carpet behind the passenger's front seat.
For the Ohio-built (78-80) Monza/Sunbird/Starfire/Skyhawk, they are usually
under the carpet behind the driver's seat. Also try the driver's side door panel
and behind the passenger's side seat backing.
Other places to look are under the front seats between the wire and foam, and
just about anywhere someone could hide one.
NOTE: The listing a company or individual here does NOT imply any endorsement
of that company or individual. Information here may not be current or correct,
but probably is. All vendors are in the U.S. unless otherwise noted.
A & M Soff Seal, Inc.
104 May Drive
Harrison, OH 45030
--> weatherstripping for doors
Lake Park, FL 33403
(305) 844-2531 or (305) 842-6065
Aerospace Components Inc.
2625 75th Street North
St.Petersburg, Florida 33710
--> 5-lug brake kits for Vega and Monza
Afco Racing Products
P.O. Box 548
Boonvillle, IN 47601
--> radiator that approximately fits H-body for V8 swap, other racing stuff
248 Depot Street
Antioch, IL 60002
--> subframe connectors, rollcages
AP&R (Auto Parts & Recycling)
W4726 Hwy A
--> used H-body parts
Auto Custom Carpet
Anniston, AL ???
Auto Decals Unlimited Inc.
11259 E. Via Linda, Suite 100-201
Scottsdale, AZ 85259
--> replacement decals
Auto Specialties Performance
13313 Redfish, #104
Stafford, TX 77477
--> street/race/blower pulleys; custom pulleys
Automotive Information Clearinghouse
La Mesa, CA 91944
--> reports about how many of a certain model of car still exist, etc.
--> Roll bars and cages for H-bodies; must buy through dealer
(ARRE Industries, Inc.)
5412 New Peachtree Rd.
Atlanta, GA 30341
--> coilover shocks for H-bodies
Carter Chevrolet Auto Restoration Service
9905 Tunnel Way
Louisville, KY 40291
John Carter, Owner
(502) 239-2545 fax
--> Vega door seals
Century Performance Center
(775) 746-4887 (try website first)
--> much stuff, including Sanderson headers
Chris Alston's Chassisworks
8661 Younger Creek Drive
Sacramento, CA 95828
--> subframe connectors, other chassis parts?
SUBRAME CONNECTORS, VEGA,
Price $ 159.00
Made out of 2x3x.083" and 2x2x.083" wall mild steel tubing. Designed to
be used with the stock floor and coil spring rear suspension. The
weld-in design substantially reduces chassis flex and does not change
the location of the rear suspension parts. Some modification to the
rear-seat-foot-well floor pan may be necessary. Kit includes a pair of
connectors and instructions
17832 Gothard Street
Huntington Beach, CA 92647
--> Camaro armrests ('78-'81 fit the H-bodies)
--> seats; direct fit for H-bodies???
Crower Cams & Equipment Co. Inc.
3333 Main Street
Chula Vista, CA 91911-5899
--> rods for Vega 2.0 and 2.3l engines (part #SP93208B)
CTC's Auto Ranch
3077 Memory Lane
Sanger, TX 76266-7329
--> H-bodies for sale
--> Buick 215-into-Vega parts
Dave's Vega Village
#4-3011 Murray St.
Port Moody, BC
Canada V3H 1X3
--> many parts
Diamond Racing Wheels
--> Custom wheels; will build in 4x4" H-body pattern
--> B&M supercharger for Buick V6
320 Thor Place
Brea, CA 92821
--> suspension kits, body parts, etc.; stopped making H-body stuff, but
still has some inventory to sell off
Don Hardy Race Cars
202 W Missouri St.
Floydada, TX 79235
(806) 983-3774 / (806) 983-3775
--> V8 swap kits
2040 Tremont Ave.
Davenport, IA 52803
--> obsolete GM Parts
--> larger 2300 valves
580 Lancaster Ave.
Malvern, PA 19355-0296
--> interior & exterior restoration supplies & equipment
ESPO Springs 'n Things Inc.
701 Pine Tree Rd.
Danville, PA 17821
--> springs, front end kits, etc.
--> custom made steel wheels, about $40 each, 15x7, 4x4 bolt pattern
Flaming River Industries, Inc.
7851 Englewood Drive
Clevelan, OH 44130-3453
--> new Vega-style steering boxes, better engineered
--> counter gear stabilizer for T5 transmission
GM Muscle Car Parts, Inc
10345 75th Avenue
Palos Hills, IL 60465
--> worldwide GM parts locater--only new-old-stock items
100 Hurricane Creek Road
Piedmont, SC 29673
--> aluminum radiators, for Monza and generic
Headers By Ed
Minneapolis, MN 55407
--> headers for 2300
--> Factory shop manuals (about $60), owners manuals, recalls, etc.
11121 Magnolia Blvd.
N Hollywood, CA 91601
--> 4.3 V6 swap kit for Vega, V8 kit; still around???
I/O Port Racing
14 Juniper Drive
Lafayette, CA 94549-3321
--> Autopower roll bars and cages for H-bodies
LaSalle, IL 61301
--> some "custom-fit" replacement items (carpet, seat covers, etc.)
plus other miscellaneous stuff
--> lots of stuff for racing, few things for H-bodies in particular
Jim Osborn Reproductions, Inc.
101 Ridgecrest Drive
Lawrenceville, GA 30045
--> reproduction decals and manuals for many cars including H-bodies
5941 Lemona Ave.
Van Nuys, CA 91411
--> restore factory dashes
--> Buick V6 performance parts
Kennedy Engineered Products
38830 17th St. East
Palmdale, CA 93550
--> Buick 215 V8 to TH350/400/Powerglide adaptor, other adaptors
17370 Alico Center Rd
Ft. Myers, FL 33912
--> exhaust: OEM dual-pipe for Spyder with 305 V8
March Performance, Inc.
5820 Hix Rd.
Westland, MI 48185
--> pulley and bracket sets for many engines
MAS Racing Products
2288 University Ave. 917
St. Paul, MN 55114
(651) 644-1635 (fax)
--> fiberglass body parts for H-bodies including many spoilers
Metro Moulded Rubber Parts
11610 Jay Street
Minneapolis, MN 55448
(763) 757-7228 fax
--> rubber restoration parts and weatherstripping
Distributors: www.weatherstripspecial.com in CA,
www.peninsularestoration.com in Victoria, BC
Miner's Mountain-O-Monzas (Jeff)
Fayetteville, PA 17222
--> used and new parts, performance parts
P.O. Box 272
Ooltewah, TN 37363
--> parts and repairs
--> redrill stock rotors for 5 lugs; misc. axle and brake parts
PO Box 875
598 Sunrise Hwy
Baldwin, NY 11510-0597
--> complete V8 kit for H-bodies, fiberglass body parts
Motormite Mfg. Div. of R&B Inc.
P.O. Box 1800
Colmar, PA 18915-1800
--> replacement parts (armrests); may make new parts--
write to ATTN: New Product Manager
--> interior and exterior trim clips for H-bodies
Performance Automotive Warehouse
--> misc performance parts
PJ's Auto Literature
PO Box 233
Reinbeck, IA 50669
--> various stuff, including dealer announcements, press kits, etc.
Performance Suspension Technology
PO Box 396
Montville, NJ 07045
--> suspension pieces
Reider Racing Enterprises
12351 Universal Dr.
Taylor, MI 48180
--> Timkin bearing and bearing race to convert to S-10 rear gears
Restoration Specialists, Attn: Dave
148 Minnow Creek Lane
Windber, PA 15963
--> will make custom window seals for H-bodies
S&W Race Cars
11 Mennonite Church Road
Spring City, PA 19475
--> chassis parts
517 Railroad Ave
San Francisco, CA 94080
--> V8 headers
Sherman & Associates
61166 Van Dyke Rd.
--> Vega sheet metal
Showcars Bodyparts Unlimited
--> fiberglass and original body panels for many makes and models
SMS Auto Fabrics
--> OEM-type seat fabrics
The Speed Center
105 N.Cambell Dept.CC
Rapid City, SD 57701
--> steel cowl hood scoops (not the whole hood)
--> complete V8 install kit, headers
--> headers for big block conversion; 2" and 2 1/8" primaries
Stencils & Stripes Unlimited
1108 S. Crescent
Park Ridge, IL 60668
(847) 692-6893 fax: ( 847 ) 692-6895
--> replacement decals for 67-up cars
1974 -75 Vega GT Stripe Kit
Kit is recreated from original GM stripes, which are around
wheel opening and have GT cutout in fender stripe.
Black body side stripe kit
White body side stripe kit
Summit Racing Equipment
P.O. Box 909
Akron, OH 44309
--> lots of stuff for racing, few things for H-bodies in particular
1325 North Red Gum #3
Anaheim, CA 92806
--> door seals for Monza
16410 Manning Way
Cerritos, CA 90703
--> V8 swap kit for Vega (part #4686)
9599 Jefferson Blvd.
Culver City, CA 90232
(310) 839-7581 ???
(310) 921-0404 ???
--> Chevy SBC + transmission mounts for Vega, part #4686
United Speedometer Server
2431 University Ave
Riverside, CA 92507-4265
--> Can fix digital clocks
Unlimited Performance Products
560 W Rincon St.
Corona, CA 91720
--> fiberglass body panels for many makes and models
U.S. Body Source
9009 SE CR325
Hampton, FL 32044
--> fiberglass body panels for many makes and models
--> fiberglass dash, other fiberglass pieces
85 N 27th ST
San Jose, CA 95116
--> Vega hatchback weather seal (no Monza parts listed)
Sterling Heights, MI 48312
--> heads, engine parts