That is one heavy car for any six to handle.
Given that I'd lean toward the 292.
But, bottom line is, if you find a good deal on a 250, grab it and try it out in there. Ditto for the 292. You might like - or not like - either one.

I like the sixes in the little Nova, but it is about 1400 lb lighter than that big Chev. So be prepared, it aint gonna be fast. Then again, wasn't the base engine the 230????