So why does LPG require higher compression over gas?
I've seen and talked to a few people over the years that have ran LPG on trucks and don't recall them saying they had to change pistons. In fact if I remember right they could run gas or LPG. One guy I talked to said he ran LPG until he got to the mountains then switched to gas for more power.

Larry, are you going to run a Carb or EFI on this motor? I'm thinking EFI might be the way to go,after all your building this motor for modern fuel it might as well have a modern fuel delivery system. Old school meets new school. Just a thought.

vince