Ok I gave up my search on 6 spoked wheels. and decided im going to get some c5 vette wheels..gunmetal of course.

They 17x8.5 with an 56mm offset

I came up with a 6.7-6.8" backspace.

Question is..do i need a 2" spacer for front and rear? If not what size do i need?

 

2" is what I'm using for 4th gen wheels, and they should be interchangeable as far as I've read/heard from various people. If you were to use a 4th gen rearend, it'd save you from using spacers in the rear.

 

im currently running the stock rear...

So 2" for all 4?

 

Yep.