['67 Bob]

I haven't been back in a while, but the 67 GTO clone is coming out great. Got the body and frame back from the shop (frame off resto) and it looks great. I picked up a 400 engine (getting ready for rebuild), and now working through the gear ratios and tranny setup with my engine shop.

For the transmission it's either going to be the Muncie M20 or a super T-10 (probably hook up to a 3.73 posi rear). I wasn't intersted in close ratio based on the type driving I plan to do, and want something that will be a direct bolt in.

I have 2 questions...
1--I'm looking for any input on Munice vs the Borg Warner - strengh and reliabilty

2--Are there certain years that I should stay away from cause they won't be a direct bolt in?
I looked at after markets but they require tunnel mods

[goatmanmitch]

Not sure about the BW, but when searching for a four speed for my car I found that m-20's are meant for 3.55 through lower numerical gears while the m-21 and m-22 are meant 3.55 or numerically higher gears.

[baron_]

tons of options
muncies built before 1966 (roughly) have a 7/8 countershaft while the ones after 1966 or 1967 have a 1" countershaft

Obviously...the 1" is slightly stronger

So, probably go for one of those stronger units
I hear people say the super T-10's might be a bit stronger...there's lots of t-10 flavors so you need to look them up
some of the later T-10's were built to be put in cars with rear end ratios near 2:93 or so, so they have a steep first gear (if i remember correctly) to compensate and get the car moving

[GT182]

Bob, check here.... http://www.keislerauto.com/gm/index.html. Or checkout http://www.gearvendors.com/ for an overdrive unit for the Muncie.

['67 Bob]

thanks for the input. I did check out gear vendors. I'm thinking their overdrive would be a good solution for the highway crusing... just a little pricey. I'll check out the other site mentioned too.

Sounds like either would be a direct bolt (munci vs BW), but favor the newer for the stronger counter shaft. I did notice several had the 1" instead of the 7/8's.

['67 Bob]

I just tracked down a super T10 with an iron case from an 82 trans am. It has a very wide ratio (1st=3.42) which would let me change my rear ratio to a 3.55 or even lower for better highway, and still getting off the line pretty good. I would think the iron case would be stronger, and assume the 82 model year would still bolt up into the 67. See any issues with my thinking? or sounds way off base...Thanks...

[baron_]

I would think it would be a bad idea....

http://www.richmondgear.com/01pdfs/pages33-35.pdf

The higher that first gear...the less torque a transmission will take
That's the big difference in the TKO500 and TKO600 - 100 pounds difference rating just cuz of the first gear

it says that 3:42 first gear would only be good for 286 foot pounds
A pontiac will destroy that, eh?

So, that's the tradeoff.

I hear that wheel hop can destroy those first gears
Plus, I'd probably like the 'wide ratio' of a muncie better - more time between shifts...

[PaulatFast]

Originally Posted by '67 Bob

I just tracked down a super T10 with an iron case from an 82 trans am. It has a very wide ratio (1st=3.42) which would let me change my rear ratio to a 3.55 or even lower for better highway, and still getting off the line pretty good. I would think the iron case would be stronger, and assume the 82 model year would still bolt up into the 67. See any issues with my thinking? or sounds way off base...Thanks...

An 82 TransAm? From the factory did those cars even have 200 hp? The factory would not have installed a trans that would handle much more than the motor was putting out. By the way, these cars all came with 305 chevys, which equals no torque! I know nothing about that trans other than Baron is correct and that will be one weak SOB. The cast iron does not make it stronger, just heavier. In short,"sounds way off base".

A Pontiac has alot of low end torque, you don't need steep gears to " get off the line pretty good". A 3.42 first combined with a 3.55 would result in a useless first gear. The factory knew what they were doing when they set these things up. An M20 or a NORMAL super T10 combined with a 3.55 gear is a great overall set up. Even a 3.42, 3.36 or 3.23 with the wide ratio trans works well.

['67 Bob]

ok.... I think you taught me a few things here. I think I'm going to go back to my original thinking, either the wide or close ration Muncie, and either the 3.55 or 3.73 rear (chevy 12 bolt is supposedly stronger and should be drop in fit).

The only thing decided so far is that the HP is going to be in the 420 range give or take. It's getting many motor upgrades (cause I can), but I don't plan to race it, just cruise and have fun. I'm also favoring the gear vendors tail piece, especially for the highway crusing. Thanks for all the great input. Ill post some pictures soon.

[GT182]

Bob, both Kiesler and Gear Vendors are a bit pricey IMO, but still the best solution to keep the power. Look at Gear Vendors this way.... I think, if I read them right. Instead of a 4 speed you'll theoretically have an 8 speed. You could use the Hurst T-handle with the button and have a pretty good looking setup to switch the od on and off.

My 79 Formula Firebird had the Pontiac 301 rated at 150hp. I'm sure the larger engines had 200 + hp. Not sure what the 403 had tho. 6.6s didn't have the hp that the 6.5s had from the 60s. You know the Feds, they made everyone cut the hp back in the 70s and 80s. Only now are we seeing the big hp cars from Shelby and Ford, plus Chrysler's new stuff. But anyways, the new cars today are lighter and their little 4 and 6 cyclinder engines are spitting out more hp than our old 60s motors. Kinda sad if you ask me.

['67 Bob]

I've added some recent pictures. It was a real rust bucket when I started, but with enough money and a great body shop, they can work wonders.