the later v's have a heat cross over and an unleaded exhaust seat. the guides on mine were sloppy and have been replaced. i didn't have any push rod issues with or without offset rockers. my heads look to have some push rod relief machined into them. of course running very high lifts may create an issue at the bottom of the head. for what i was doing at the time the heads were better than what i needed. if it weren't for the guide issues i'd never taken them off. they were replaced by edelbrocks but in my estimation the v's made more power.