[ocnevo]

I have a stock '69 Chevelle w/350 cid and a factory 3 speed. I am currently putting in a
B/W Super T-10 4 speed. What effect will this have on the stock rear end and or Engine RPM?

 

[1966_L78]

There shouldn't be any drop in RPM in top gear (assuming both are 1:1 top gear).

But usually it will give better driveability and better off the line accelaration because often the four speed will have a lower first gear ratio, which helps get the car rolling... Also usually less RPM drop in between each gear change... It allows you to keep the engine in its ideal powerband more.

Really it is transmission specific, so the gear ratios of each would need to be known...

But no effects on the stock rear end either...

 

[MalibuDreamer]

Originally posted by 1966_L78:
the four speed will have a lower first gear ratio

Not always the case, I have a 3 speed with a 2.86 first gear ratio 1:1 final drive.

4 speeds will be more fun to drive though.

-Ryan