The XE 274 cam is a bit bigger than the RA4 above .050 lift, because it has a very aggressive ("steep") ramp, and more lift. And I know for a fact, the RA4 cam is a bit nasty in a 350, without Rhoads lifters.
So I would not try to run the XE 274 in a street 350. That's just my opinion, and that's all I'll say about it.
