This FAQ is a compilation of my experiences as well as other's with the V8 Chevy Monza, Vega and other H-Bodies. There are some sections that have no information in them yet, but I'm always adding to it, so if you don't see what you're looking for check back regularly or e-mail me. Also, read this information the same as any information you find on the internet and make your own decisions about what you read. If you find errors, have any suggestions, personal experiences, or information you think would be useful here, please e-mail me. I make no attempts to mislead you, I only know what worked for me and I won't be liable for any damage to equipment, injury to persons, errors in judgement, or depletion of your finances. Hey, I gotta protect myself.
Gear Ratios and Identification Codes (Checkout this Page!)
Rear axles can be identified by a code stamped on the front of the right axle tube about 3 inches out from the carrier and 30 to 45 degrees above horizontal or on a metal tag attached to a rear cover bolt.
Truck Gear Modification: (Adapting the Chevy Gear Set)
The 7.5" Chevy S-10 gears will fit the H-Body case, but for installation in an H-Body rear the S-10 pinion gear requires Timken bearing #16143, Timken bearing race #16283, and National seal #8610, S-10 pinion yoke, and "Combination" U-joint (Dana #5-3022X). The bearing and race are for the gear-side of the pinion, not the yoke end. The yoke end bearing and race (of the pinion) are the same as the factory parts (Timken bearing #M86649 and Timken bearing race #M86610). However, you can machine the S10 pinion gear to fit the factory Monza bearings. I just prefer to use the bearings mentioned above instead of modifying the pinion so that the integrity of the pinion won't be compromised. As with most all gearsets a specific gear carrier is required for a specific range of gear sizes. So, the carrier must be the correct series for the gearset that you want. In other words, you need to know what series the carrier is or what gears were installed on it from the factory. A 2-series carrier fits 3.08 and numerically lower gears (3.08, 2.93, 2.73, 2.56, and 2.29). While a 3-series carrier fits 3.23 and numerically higher gears (3.23, 3.42, 3.73, and 4.10). The exception to this is if you purchase custom gears specifically made to fit your specific carrier (i.e. you can buy 3.23, 3.42, 3.73, 4.10, and 4.56 gears to fit the 2-series carrier). Also, the Camaro and S-10 7.5" posi unit will fit the 7.5" H-Body rear housing. I have had a posi carrier from a Camaro 7.5 rear installed in my H-Body rear since 1988 and it works fine. Remember to get the 26 spline unit as all H-Body axles are 26 spline. However, if you get the axles and carrier from the same vehicle (S10) then they will obviously fit.
I've been told that PAW sells a posi unit that fits Monza rear axle assemblies. Can anyone confirm this (if you know e-mail me)? Remember to refill the case with the proper lubricant for the positraction or you will likely burn it up.
5-Lug Rear Axle Upgrade: (Using 82-93 Chevy S-10 and Blazer Axles)
I have tried this modification and you can only use 2-wheel drive Chevy S-10 and Blazer axles (from pick-ups only?) for a 5 lug upgrade. The axles are the same spline (26 spline) and are only 1/16 of an inch shorter. In some cases the shorter axles result in the rear brake drums (also 5-lug) rubbing against the rear backing plates (dust covers) around the edge where the drum meets the back cover. The backing plates may need to have about 1/16" shaved off the lip facing the drum to prevent rubbing. Mine do not rub, but if you find that yours do just remove 1/16th inch from the edge of the backplates. To do this, I would suggest scribing the backplates 1/16th inch in and using a handheld grinder, remove the excess metal. Then smooth the edge with either a file or sandpaper. NOTE: 1975 and earlier vehicles have 9" diameter by 1" wide brakes and therefore a smaller backing plate. Later model (1976 to 1980) backing plates will be required for this modification. Currently I'm using 9" wide 15" dia. Centerline Racing wheels with 3" rear spacing. The 295/50R15 tires are 11 13/16" wide at the shoulder and have a 10 1/8" tread-width. Being mounted to the factory 7.5" rear, the tires extend about 1 1/2" out from the fenders and clear the inner fender wall by just 11/16". Next time I work in this area I'll install a narrowed Ford 9" rear and rear subframe with a capability of mounting even larger rear wheels and tires. It will be designed in a way so that I can still use a wheel and tire combination like that mentioned above for street cruising, but tuck them under the fenders.
3 Link (Torque Arm) and 4 Link Suspensions
The factory 3-Link Torque Arm Suspension was the best design by far. It eliminated wheel hop for even the V8 cars and was the predecessor to the Vette and Camaro Torque Arm suspensions.
Currie Enterprises Inc. Ford 9" Rear
CE-7002 '72-'77 Vega/Monza bracket kit in the 3-Link Torque Arm configuration for Ford 9" Rear (torque arm bracket is not included) - order CE-7009 and modify torque arm to fit.
CE-7002A ('72-'77 Vega/Monza bracket kit installed on new or customer housing).
CE-7009 Torque Arm Bracket, ’82-’04 GM F-Body Weld-On Torque Arm Bracket - Fits Camaro/Firebird. ($149.95 as of 2009)
12-7008CTR 12-Bolt Housing (Center Only) for Torque Arm Cars. ($449.00 as of 2009)