so i got the block out and now when i took it in to get it bored the guy told me i need to have the oversize pistons first. i told him .020 over but he said that they could be off by just a tiny amount and they need the pistons so they can match the holes to them. so my question is should i go .020 over or .040 over? these are the only sizes i can find. i dont want to buy .020 over if they need to bore it out to .040 over to get the cylinder walls smooth. o and my other question is what i with these dished pistons are they better than the stock looking ones? i found wisco dished ones for the same price as JE ones that look like the stock pistons. what makes more power?