What 4 speed do I get
 

Working on a 1976 firebird with the 400. Currently no transmission in the car but was originally a 4 speed. Been looking online and confused as to what transmission I need. Says the Muncie 4 speed was only made until 1974 and I read the Saginaw 4 speed was for 6 cylinder cars. Read there’s also a Borg Warner t10. What transmission did this 76 firebird have from the factory?

It was originally equipped with a Borg-Warner Super T-10 with a first gear ratio of 2.43:1. Richmond Gear still produces them.

https://www.richmondgear.com/wp-cont...hmond/RG25.pdf

Ok thanks, so at the same time a Muncie would fit that 400 no problems? Muncies seem to be priced lower.

Depending upon the Muncie, it should be a direct swap. It’ll need to have a 26 spline inout shaft and 32 spline output shaft. You’ll also need proper shifter linkages too.

You can always buy a used ST-10 in excellent condition. I’m not sure what the ratio here, but this may be an option for you if you need more than just the trans.

http://forums.maxperformanceinc.com/...d.php?t=843195

And the ratio doesn’t affect installation. It’s simply torque multiplication in gears First to Third. It also affects power rating, which you’ll see in the Richmond chart.

If I were doing 4spd esp I'd buy new. If you are going to modify engine at any time. It wouldn't be original but I'd look into Muncie with the supercase. Little pricey buy I've broken early t10s,weak trans,4spds, had to be towed more than once. Super t10 is better.

I am helping a friend look for a T-10 for a 79. I have heard that these are everywhere but apparently not. At least not a 79 model, especially one price right.
IF originality is not an issue, I would consider putting in a new 5 speed. I know a couple that have gone that route and loved it.

The ST-10's for the 301 had different ratios, so be aware of that.