I have had a SBC sitting around for a while... I always assumed it was a 350. I decide to scrape the casting number area clean. To my dismay, it says "GM 5.0L G" which I assume means a 305 gas motor. Is there a way to identify what is inside without tearing it apart? Is there any chance that it has roller lifters? If it were a roller 305 it would cover up some disappointment.