.030 with new pistons? What's the compression height of them? Motor homes engines replacement pistons are deep in the hole and are low compression. How much experience do you have with engines? Enough to understand what compression height of a piston is? What is the piston ring type? Moly is good, run from chrome unless you plan on dirt track racing. At least that's the way is was years back. He listed a lot of name brand parts but didn't list any specs on them. His price is very low imo for all of those name brand parts but there's not much info on specs. If he can't answer questions on them, then he's blowing smoke. If he can, go look at it. If there's RTV oozing everywhere, walk away from it. Even if he wiped it off on the outside, you can't clean it up on the inside. The more engines you look at, the better you can tell if someone knows what they are doing and even then, there's no guarantee but spending time around engines and people who build them does help you become more educated imo. And at the very least, take a compression tester with you and check it out. If it's a running engine that is broke in, it should give you a good test.