L98 heads and dome pistons
Use a marker to shade the area on the piston that's hitting. Using the gasket that you will assemble the motor with, set the head in place with 3 to 4 bolts. Roll the motor over until piston contacts head. Pull the head off to see where it is hitting. You will have to feather back (grind) the dome in this area. If you do not feel comfortable doing this take it to a machine shop. If there is too much dome preventing you from bolting the head you probably will have to buy new pistons. The L98 heads were probably designed for use with flattop and dished pistons. They are 58cc chambered heads. You need to know piston volume (+12.8cc or +8.00cc) which with these heads will give you a compression ratio 12 - 14+:1. The rotating assembly will have to be balanced after grinding pistons.