Although there have been a few crossovers in gay porn porn and body building (Samuel Colt and Jim Ferro come to mind), there are few actual pro body builders who did hard core porn.
Unfortunately for me.
Chris Duffy aka Bull Stanton really did do both, although his hardcore career was short. While dating Blue Blake he made The Wild Ones and Nothin Nice, along with some solos. I actually have seen and enjoyed his scene from The Wild Ones, but a lot of his work is very dildo heavy which I find dull. Apparently there was a fall from grace (although the story in that link is quite homo-phobic and rife with misspellings which makes me doubt its veracity).