How do you think a M22z with a first gear 2.98 and a 3.36 rear gear would perform. The output drive ratio would be 10.01 for 1st gear which would be a power horse off the line. Would it be too much?

Here is how the final output drive ratio compares. The biggest difference is 1st gear. For a performance car, the recommended 1st gear output ratio is 10.

M22Z
1st gear final drive ratio = 10.01
2nd gear final drive ratio = 6.85
3rd gear final drive ratio = 4.93
4th gear 3.36


Current M20
1st gear final drive ratio = 8.47
2nd gear final drive ratio = 6.31
3rd gear final drive ratio = 4.91
4th gear 3.36

What do you all think about this swap?

Sounds great. I've got a 3.23 rear and plan to go that route. They also have some different choices for 2nd and 3rd gear ratios

Do you think the 1st gear would be pushing to many rpms and have to get out to quick?

I've heard the number 9 for 1st gear final drive as being a minimum. Mine is 8.14 which is OK for casual driving but sucks for performance. Your 8.47 isn't much better than my setup. I would think the 10.01 would be good. Others can weigh in.

Here are the ratios available:

http://www.autogear.net/wp-content/uploads/2015/05/Syracuse_modular.pdf

There's a decision for the 2nd and 3rd gear ratios.

Which ratios for 2 and 3 were you thinking? The 2.225 2nd and 1.46 3rd looks good.

I don't know. Footnote (3) says the 2.043/1.468 "gearset offers nearly identical rpm drops between gears, so-called 'Geometric' spacing." That sounds like the way to go. Some of the ratios are favored by road racers. You can call them and discuss it. Our local Pontiac club took a trip out there to Autogear and we spent a lot of time discussing transmissions. They seem to know what they're doing.

Bob, since you visited their site what do you think of them? Would you feel purchasing from them? I have seen a couple builder of the same transmission. Paul down in Fl with 5speed.com builds them too. Trying to decide who to buy from if I go that route. Thinking pretty hard I might lean that way.

I'd definitely recommend Autogear. They've been doing this a long time. They source all the parts including the aluminum castings and gears from long time suppliers. The gear sets come from a gear maker in Italy. A lot of their business is custom transmissions for racers. They will also rebuild your numbers matching trans.

I'm planning to get one of their trans soon. My 4th gear synchro is shot.

I think I will hold off until I hear from others who have tried installing the super case in there 67-69 bird. I would like to see if there are any fitment issues that have to be corrected. Also any issues with the Hurst shifter.

I think I may learn how to rebuild these gearboxs and order the m22z gearset and put it in mine. That would be a nice little project over winter. If I don't like it, I just swap it back out.

Harold, I blew out my input shaft gear and a few teeth off first and second in my M20 a few years ago. Had to source some new parts and a rebuild kit. I'd never done one before but it's not like an automatic, like magic or something. Pulled it apart and put it back together with the new stuff. It wasn't that difficult. Seems like there was some issue with the reverse shaft and gears had to go in at the right time. My other concern was I didn't put any sealer on the countershaft before it went in. All that said, it's been on the shelf for about eight years now because the replacement Trans I bought till I got my original done works fine and I see no reason to change it out until I need to. So I really have no idea if I did it right or not.😎 Never hurts to have a spare laying around though.