1969 - 1970 Firebird Muncie 4 Speed Transmission, M-20
Complete original GM Muncie 4-Speed Transmission for your Firebird or Trans Am. Professionally rebuilt and guaranteed for 1 year. If you want to race or speed shift a transmission at 6000 RPMs, DON'T BUY A Muncie. For Street Applications they are perfect. Don't forget to choose your year model needed from the drop down menu. Most Firebirds left the assembly line with a M-20 ratio. Features a 2.52 first gear and is a great combo for street cruising.
*Please double check your clutch and pressure plate set to match below.
69-70 ~ Input Shaft = 2 Grooves with Coarse 10 Spline Count
1969 Main Case = 3925660 (Pictured)
1970 Main Case = 3925661
***Note: This Transmission is shipped factory direct. Please allow 4-8 weeks for delivery. Shipping charges will apply for all in-store pickups and show deliveries.
PART NUMBER: TRA-617
- The Muncie M20 is basically a wide-ratio transmission and was intended for normal street driving use. The M20 units have a 2.52:1 first gear. The M20 is most compatible with GM 3 Series rear end differential gear ratios such as 3.08, 3.31, 3.55, 3.73, etc. They are for economy and street drivability and just cruising.
The Muncie M21 is a close-ratio unit, ideally designed to be matched with lower gear ratios such as 3.73, 4.11, or 4.56 GM 4 Series rear end differential gears. The M21 units have a 2.20:1 first gear. A close-ratio gearbox keeps shift points closer together, which keeps rpms up. The M22 has higher-nickel-content straight-cut gears. It uses much the same gear ratios as the close-ratio M-21, but can take more abuse. An M22 retains less heat due to its straight-cut gears and the lack of thrust that helical-cut gears create. An M-22 holds up really well, the downside is it tends to make noise. It will rattle at low rpms and whine at high rpms.
The Muncie M22 is also a close-ratio unit, ideally designed to be matched with lower gear ratios such as 3.73, 4.11, or 4.56 GM 4 Series rear end differential gears. The M22 units have a 2.20:1 first gear. The M22 is the one and only "Rock Crusher". Some people think all Muncie four-speeds are Rock Crushers, but they're not.
*PLEASE NOTE ~ THIS TRANSMISSION IS SHIPPED DRY. ALWAYS USE REGULAR 80 / 90 GEAR OIL SIMILAR TO OUR DRIVEN PART # 04530.
|
