Hahah, that's what people always wonder. "OMG UR GONNA THROW OFF THE 50/50 WEIGHT DISTRIBUTION"
First gens never had exxxactly 50/50 distribution, but that's besides the point.
As far as the weight difference goes, maybe like 460lbs VS around 375lbs? I'm guessing, but that 460lbs is a factory 302. Strap some aluminum heads on, smaller starter, etc. and it gets even lighter. Really doesn't throw anything out of whack... I just get a shit ton more power. AND TORQUE. No holes in the hood, everything tucks really nicely into the Rexs' engine bay, it's crazy.... It's like it was made for the V8. The swap is simple, flip the stock RX7 crossmember backwards, and buy an adapter for the trans. of your choice, I went with a (fully built) AOD. With a T5 I think I'd just sit there all day spinning the back wheels in 1st gear. Been talking to a guy with my exact swap, more or less, his 302 is carbed not fuel injected. Bone stock engine and Mickey Thompson drag radials and he ran a 13.1 1/4
If any of you guys are interested check out
http://www.grannysspeedshop.com/ they're the go to guys for 1st 2nd and 3rd gen RX7 V8 swaps. You pick your poison, 302, 350, LS1, hell they even have parts for a Nissan V6 conversion.
It has a 5 lug swap, utilizes 2nd generation RX7 Turbo II Calipers front and rear. OEM BBS wheels from a 2nd generation convertible. 11lbs a piece!
Front: (Wheel well is now painted black, like the rear. Nice and clean)
Back:
I've also got a 100 shot of giggle gas for it... should get me into the mid to upper 12 second range.
Here's a video I found awhile back. It's great. Terrible driving and lotssss of power... enjoy
V8 Renegades Video
This one is the guy I mentioned, stock 302 on drag radials. Try to ignore the music......fuggin fallout boy -_-
1985 V8 RX7 GSL Ford 302 Swap