I have a question reguarding the b20a piston and the b20a5 piston. Both are different even from the same year. I have been trying to find a piston for the b20a, but I have only found the b20a5 pistons. I installed the piston unit including the rod, I am not sure that the clearance for the valves will be there on the b20A5 piston. It does have the indentions for the valves and it is countersunk giving it a little more room then the b20a original pistons. I am just worried of the valves not having the clearance they need. Can anyone help me?