18x10 wheels on stock subframe 1st gen.

[Pete68]

Im running 275 on a 68 camaro with rolled and cut fenders (which you cant tell from the outside). Fits with lots of space on the inner area, maybe a half inch. So yes I think you can do 10in wheel. Offset needs to be spot on and tire diameter should not be too big. Im running small tire diameter 275/35-18