I bought a car with afr 185 heads and i took them off and they have the part #1387. I looked it up and those heads have big 72cc combustion chambers. I am in the process of rebuilding a 347 and the car is N/A and i want to have 10:1 compression.I could get them milled down, or should i get domed pistons? I have heard from some tech guys that domed piston will increase detonation and not allow me to run pump gas. Any body have any experience with domed pistons and pump gas?