# 68 transmission 4 speed question



## matt68gto (Mar 22, 2006)

How you Know if I have a Close ratio Transmission? I got the build sheet from phs, but I Don't see the exact code for it. The car came with a 400HO, 4-speed, and a 390 gear.
matt


----------



## lars (Sep 28, 2004)

Just raise the car up, put it in 1st gear, release the parking brake, and have someone turn the crankshaft over 1 revolution while you observe the tranny output shaft. If the output shaft turns 2-1/2 times, you have a wide ratio. If it turns 2-1/4 times, it's a close ratio.

Gear ratios for 1st thru 4th:

Muncie M20 wide ratio 
2.52 1.88 1.46 1.00

Muncie M21/22 close ratio 
2.20 1.64 1.28 1.00

A car with a steep rear gear (like your 3.90:1) can take advantage of a close ratio. The lower gears (lower numerically) feel better with the wide ratio due to the better gear multiplication in 1st.


----------



## kerno (Apr 6, 2006)

If you'll post what the tach reads at exactly 50 mph or 60 mph in 3rd gear and tell us the rear tire size, we may be able to tell as well.


----------

