Late 80's swirl port heads 302/714's

I'm curious about the water heated intake crossover on a 318 engine. What intake manifolds were those? Could a stock cast iron manifold be modified for that? Should I put this question in a separate thread?
Thanks, Richard.

I'm interested is this also....I'd think a guy could do a little pressure test on the intake to make sure water doesn't get in the oil....or just block it off some how.

Inquiring minds want to know man....LOL