I'm in the early stages of gathering parts to build a motor that essentially mocks the one I built 30 years ago for my old red Stage 1. The plan is a "warmed over" Stage 1 motor that has some umph and may occasionally make a pass down the quarter mile. Since my Muncie is original to the car, using that isn't an option and it will be shelved. I have a lead on a M20 that I'll have rebuilt and was wondering how much of a noticeable difference there is between that and the M21? Rear end is 3.64. So, what say you?
M20 will be "more street friendly/fun", better street gear ratios. Other than that, they are pretty much apples.
I would reccomend you check out an autogear trans before you put money into a stock muncie. Especially if you're planning on hitting the strip. For a few bucks more you can have a bulletproof trans and you can pick your ratios.
Main difference is the M20 will have a steeper first gear and larger gear spreads than an M21. For a 3.64 rear either would be fine, but I too would probably go with the M20 gearset as you dont necessarily need the close ratios for your application.
Think they have m20 ratio gear sets available that are identical to the m22's angle pattern. Gotta have that whine!
I have that gear set I'm my GSX, the whine is bad ass and the big block works great with the wide ratio gears.Also my brother shredded the input shaft and cluster gear on an m20 with a 455 in his GS. He wasn't even beating on it.They have a tough time with the big block torque. Tim
I am running a m22 with 3:90 gears and 12.5 X 29" tall tires in my GS. It's fun to drive. However, I have to take off easy so that I don't blow the tires off it.
Autogear makes a M22-W, same gearset as a M20, with the strength of the M22. I have one for my GS,we'll see how it works later this summer when the car is finally finished
I too have a wide auto gear gearset in my car that is straighter cut like the m22's. It's not exactly an M20 ratio, it was tweaked slightly, but close.
Mine isnt a conversion done to a factory trans, my transmission is an all new autogear supercase unit built by Midwest Muncie. You can buy the gear sets many places (including autogear directly *I think*), but in know the place linked below is well known for quality parts. http://www.5speeds.com/cart/index.php?route=product/product&product_id=154
Brett, I got the gear set from autogear. It is a m22 wide ratio. I actually used the case from the m20 my brother blew up. I got the gear set , rebuild kit ,a steel center bearing carrier ,and a wider front bearing. It was $981 bucks in 2014 with shipping.
I bought and used Paul's video as a reference when rebuilding my first Muncie. It is very thorough and well done.
