Greetings.

I was doing research on this site about gearing and it really got me thinking. I was planning on building my 68 chevelle with a 3.73 posi rear and a M21 muncie.
Honestly, what are your thoughts?
Should I use a M21 or a M20? I plan on occasional strip and mostly street. I don't plan on any trips over 120miles long. I want some serious g-forces when I stomp the throttle. I also plan to build a fairly stock 396 cu in.
I never drove a wide ratio verse a close ratio transmission chevelle, so I cannot imagine the difference. Here are some things that I must use:
1. A 4spd transmission - Saginaw or muncie or the new richmond 4spd? (I really don't want to pimp out my 68 with a modern 5spd or 6spd)
2. Stock 10 or 12 bolt rear end
3. Fairly stock 396 chevy.

I appreciate any comments that you may have...

Super-T10 2.88 1st gear and 3.73's will have some throttle response

Between the M20, M21, M22 the M20 will give you the quick out of the hole feeling and will do better then the other 2 Muncies in the 1/4 mi and from light to light runs. But also remember that you now can get M22 Wide gears, so you have the best of both Worlds, the quick 1,2,3 shifts and the beautiful whine sound of the M22.
The M21 and M22 will be a slouch off the line unless you have at least 4.10 gears or lower.

I've used an m-20 with a 331
it was pretty nice on take off
then when I stuck the m-21 in it after I blew the 20 - it was definately a bit of a dog on take off

I chose an M20 for my car because of the lower first gear ratio. The 4.11 in my car, along with the 32 inch tall tires makes it about the same as a 3.55 in the average muscle car.