i am currently in the process of putting a sbc 350 into my 81 280zx i have a good running turbo 350 with overdrive laying around in my garage i was wondering would this be a good tranny to use for a street car what would it top out at and could it be driven on the highway any help would be great thanks

 

I think that's a fairy common tranny for a 350 swap. You can also change your rear diff ratio if you're not too happy w/ the tranny gear ratio.
Here is a tight design page for Z car trans & diffs... you can swap around parts & see what your launch & top end will be. I've spent plenty of time here:

http://www.geocities.com/z_design_studio/

 

Hey man, I have 350 also, but I use a 700R4, due to the extra gear. Believe me, running that turbo 350 in third gear on the highway would not be good for you, your car, or your wallet. It all depends on you though. I have a lot of driving to do everyday. All highway, but in excess of 80mph+ for at least 80 miles/day. Third gear in that kind of travel wouldn't be good. If you live in a small town, and don't really get about 60mph (unless showing off ) then I say go ahead and go with the Turbo350/