My 340 build

If you go the felpro, I would retorque them. I have had issues when I didn’t. Torque them then let them sit over night and back each off a 1/4 turn and retorque in order. I agree you surface would be fine for cometics. Search what grit the recommended RA converts to. It will give you a better understanding of how smooth it needs to be. I run cometics no issues. To be honest I think there was some confusion of water leaks with cometics on LA’s and it wasn’t surface finish it was actually the wrong gasket. IIRC you needed to run a w2 gasket if using a r block or something like that. Its been years since reading up on it.