What specifically keeps the v6 version of the 700R4 from bolting to a v8. Throw me a bone here guys, I'm trying to educate myself.

Thanks.

capt68

 

Bellhousing - a V6 (well, most V6's) are 60 degree engines (the pistons make a 60 degree angled V shape), and a V8 is a 90 degree engine - so the bolts, studs, and mounting holes are in different locations between the two.

I'm not 100% sure, but I think the V6 version is also not as stoutly built.

 

If you do it, the trans WILL fail, sooner than later.
This:
http://www.speedwaymotors.com/Chevy-...ates,3280.html
will let you do it.

 

Thanks for the link ronnjonn! Here is another question... Is the structural integrity of the v6 case the same as the v8 case? In other words, if I put a $500 rebuild kit (fake senario) in to the transmission to withstand 500 ft/lbs of torque, would it stay together or is the case weaker? Thanks for taking the time to educate me on the subject.

capt68

 

All I can say about that is that I have read about people putting the 'vette guts in the V6 case, for use behind a Cadillac Northstar swap into a rear-drive car. No adapter plate needed for that.
But what you propose...
If your V6-spec 700R-4 is still working right, you can sell it for enough to just buy the correct V8 case at the salvage yard. I've bought a fully functional 700R-4, from a t-boned '89 IROC-Z, for $120. It even came with a 30 day exchange policy, in case there was any problem with it.
If you're willing and able to do labor to save cash, then this is an option.
Also, even if you can successfully install a top-quality kit, for like $350, it's still limited not only by the sun shell, IIRC, but the V6 version is still only a 27-spline. The drums aren't machined to hold as many clutches, either.
Look, your V6 version has the tailhousing with the torque arm mounting provisions, so your V8 trans can be from a C1500 pickup, or a Caprice, or whatever. Preferably '88-'92.
Just get the right thing to start with, this is not a worthy battle to be fighting.

 

While you are correct about the 27 spline shaft the drums and shell are the same between v6 and v8 versions. the difference is in the apply pistons and and plate thickness. the biggest limiting factor is the case and if you do the case swap, might as well rebuild the entire unit with the v8 clutch packs instead of just swapping the internals.

 

Hey guys, thanks for the helpful info. Fixing to start a project that has been sitting in the shop for the last 2 years and it is time to get started. I have done all the research, Just needed to get that tranny question out of the way for my own personal satisfaction.

Thanks.

capt68

 

As mentioned, it's just not worth it. Your spending hours and dollars trying to save seconds and pennies. Just get a V8 700R4 and be done - ESPECIALLY if your goiing to have anything above 200hp in front of it.

 

Thanks for clarifying, Jeff. Seems I wasn't remembering correctly. But close enough.