I took my lly heads to get machined. when I got them back the heads were rough and I was told they need to be almost a glass finish. So he sanded it smooth. We started putting the engine back together and my buddy who is doing the work said he didn't have enough clearance between the valves and piston. Took it to another shop so they could measure everything and it came back that the shop took .020 off. Any ideas on a fix since the c grade gaskets aren't thick enough or are the heads trashed now.