I have a 79' GS and I am doing a 91' 13b n/a swap. To keep me from cutting away at the body to fit a 91' tranny, Im planning on using the stock 79 tranny.
My question is, how much of a weight difference is there with this setup? I was considering using the 12a flywheel/clutch/pressure plate until I could buy a new set, but Ive been told that I need to use a 13b flywheel/clutch/pressure plate ASAP to keep it balanced. Is this right?
Also, are the 13b flywheels the same length in diameter as the 12a, to use the 79' starter, or does it not matter?
Thanks

 

i beleave there is a post..you can change the rear tail shafts i know they did it with a 79 12a tranny and a 85 tranny...i would check that post and see if you can do the same thing with the 13b trany

 

Druken,

I'm interested in the answer to this as well. Here's some info that I've found in my research.

From Felix's interchange site, we find the following:

Transmission length: Should be no problem.
Suitability:
1979 is in 'Group 1'
1981-1985 FB's are in 'Group 2'
The S5 transmission is in 'Group 3'

Here's a couple quotes of interest.

"Group 2 boxes can have the tailhousing and complete shift mechanism from late 1980 boxes installed for use in Group 1 cars."
"Group 3 boxes can have the shift mechanism from Group 2 boxes installed for use in Group 2 cars. The expedient way to do this is a complete tailhousing swap."

Which leads to the question...can a Group 3 box have the shifter mechanism from a late 80 box installed for use in a Group 1 car? This is the option I'd like to pursue.

Another option is to modify the transmission tunnel to suit the FB shifter location, and install the 81-85 Group2-configured transmission.

 

Ok, you need to use the flywheel and clutch that goes with the 13B. If you use the flywheel from the 12A your engine will be out of balance and will eat itself alive. All starters on rotaries are the same so you won't have any problems there. As for the transmission, I do believe that the '79 transmissions aren't as strong as the later '83 and up transmissions so it might not stand up to the turbo motor. You'd be best served using the transmission from the TII and modifying the tunnel for the shifter or swapping the tailshafts. Someone 'round here just did that I think.

 

Thanks for the info. My swap isnt with a 13b TT, its an n/a so I dont think the that will be a problem with the "not strong enough for the motor". Thanks again, info helped a lot

 

Yeah, I don't know where I got that from.

 

use the 13B clutch and flywheel to keep the engine balanced.

as long as your tranny is healthy, use it.

 

i have a 4 port 13b with 91 n/a internals. i have just recently purchased a fidanza. id sale you my stock flywheel for cheap. it all depends on how soon you need it. im not sure when im going to install the fidanza, im dreading it actually. let me know if youre interested.

 

uh....all starters ARE NOT the same!

 

Will the stock starter from my '79 tranny work with a N350 flywheel?

 

An '86 NA starter will fit a '74 REPU with minor casting falsh removal in the hole. 1st gen trannies don't even require this step. The starters are indeed not all the same, but they are interchangeable amoung NA setups.