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Old 06-23-2010, 02:37 PM
MouseFink MouseFink is offline
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Think about that decision

Originally Posted by 77'Omega
ok im going with the pontiac 400 and as for the trans some one is picking it up on there way through okc but it was 75 bucks and if it explodes after puting it in ill just get a different tranny plus i have a buick trans in the shop that looks just like the pontiac trans siting next to it. the buick tranny being a good one and the pontiac having huge holes and cracks all over.
thanks for all the input, i will up date on the 4 spd
GM has not made a "traditional" Pontiac engine since 1978. In the start of the 1979 producton year, GM had 20,000 Pontiac engines on inventory and they installed them in new Pontiacs and used them for service replacements through 1981. In 1982 and later, all Pontiacs received corporate engines.

1962-1963 Poantiacs used Borg Warner T-10, 10-spline 4-speeds.Thease are very weak transmission and unreliable with engine torque over 400 lb. They have narrow gears because they stuffed 4 speed gears in a case desigend for a T-85 HD 3-speed transmission. The T-85 3-speed was actually a stronger transmission.

Note: The 1963 421 HO and 421 Super Duty Pontiacs used B-W Heavy Duty T-10 10-spline 4-speeds that were introduced for the 1962 - 1963 409 Chevrolets. Those transmissions had an aluminum main case and tail housing with high nickle gears. They are very rare and sought after by restorers today. The early B-W T10 had problems under a high torque load and the weak mid plate (bearing support) allowed the transmission to twist. The reverse idler gear would move over about 0.250" and clash with the main gear and break the main transmission case like it was an egg.

1964 - 1974 Pontiacs used Muncie 10-spline 4-speeds, M21 and M20.
1967-1970 Pontiac Forebirds and Tempests with 350 engines used a Saganaw 4-speed.
1973 - 1979 Pontiac Trans Am, 1973 GTO and Firebird 400 or 455 SD used a Borg Warner T-10S (AS-9) 26-spline 4-speed. The so-called Super T-10.
1970-1972 Trans Am 455 HO used a either Muncie M22 Rock Crusher or a B-W T-10S 4-speed. A Muncie M22 4-speed was rare in a Pontiac.
The 1970 - 1974 M22 is sometimes confused with the 1970 1974 M20 and M21 Muncie 4-speed becaue they all use the same large diameter main shaft and TH-400 U-joint yoke.
1975-1979 Pontiacs used Borg-Warner T-10S (AS-9) 26-spline 4-speeds.

All GM manual transmissions will bolt up to all GM bellhousings and the 10-spline or 26-spline pilot shaft will fit all GM crankshafts. Pontiac engines have used the same #7101 ball bearing type pilot bvearing since 1934. Be advised, many 1967-up Pontiac crankshafts were not finished to accept a manual transmission pilot bearing. Before the engine is assembled, a machine shop can finish the crank for a pilot bearing. Pontiac pilot bearings are becoming rare at parts stores and cost about $27 when yiu find one. The good starters are now made by the aftermarket suppliers. Rebuilders have rebuilt all the old Pontiac starters to death. Rebuildable large valve (2.11"/1.77") cylinder heads such as those originally installed on 1967-1970 GTO and Firbird 400 and 455 engines are nearly impossible to find and when you find a pair of those heads that are rebuildable, expect to pay big bucks for them. Pontiac blocks and cranks are in the same boat.

You will spend most of your time looking for parts. Leave the antique Pontiac engines to the restorers.

Last edited by MouseFink; 06-23-2010 at 03:08 PM. Reason: spelling
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