why re-invent the wheel here? Copy what Rod Millen did part for part, he kicked some serious butt with that car and it was reliable from what i recall. It worked for racing so it should work for you....

For the record,Millens 1983 conversion added only 100lbs,on the tube chassis 300hp car.It used 626 front suspension and drivetrain and a special adaptor to fit a transfer case made by Weismanns Transmission Research and Developement,to the tranny.Sounds pricey,but it was light and had a higher top speed than Buffum's Audi.
Millen had two wins that year,but lost the championship every year (usually to Buffum) until he won in 1988................in a 323GTX.

I'm interested in it for my 78-79 sa22c rx7 and add an air shifter. Would be really nice

i want to try that in real life, just walk up to someone and continue a conversation from sixteen years ago

Not mine, but I'm just here to feed the necromancers.

https://cimg2.ibsrv.net/gimg/www.rx7...78e3900eb1.jpg

Series 3 4wd rx7
 

I’ve heard and seen a few good ideas on the thread, I’ve completed the conversion in a dirt circuit car tight squeeze and a lot of custom bits but easy enough
https://cimg7.ibsrv.net/gimg/www.rx7...d737a2da7.jpeg

The series 3 is running 13b turbo EP and a 4wd not awd , running full transfer case etc. was running rear wheel drive prior in my class but to hard against my competition on clay surface so I went 4wd, is a rocket for what it is
https://cimg3.ibsrv.net/gimg/www.rx7...6ccd188ce.jpeg

Super Cool! What transmission, transfer case, and front differential did you use? I would definitely be interested in hearing more about your build.

Bit overkill but fullybuilt th350, 3200 stall, suburban transfer, wrx diff in the front series 3 rear with Cusco lsd both running 3.9, 50/50 drive front and back

As stated by others a Subie AWD drive-train would be the easiest, trans adapter plates already exist to drop rotaries into subies...

No doubt but motor sits way north of crossmember , wanted to keep my centre of gravity similar to keep the handling of FB 50/50👌

Have also performed the setup you mentioned but as I mentioned was a pig and a lot of mods to get it to not understeer , but was in a escort and saying that the engine would be in the nose cone of rx7
https://cimg4.ibsrv.net/gimg/www.rx7...3e2cc9094.jpeg