I'm thinking of building an engine for propane only for my Bronco. I know I need higher compression than normal to get the most out of it and be close to the HP I can get with gas. I need about 11:1. I have a good reworked head with 52cc chambers. The engine is bored 30 over now and will be 40 over after I rebuild it. Would zero decking the block and running flattop pistons get me where I need to be? Any one else running propane on a I6. I know of one other Bronco doing it but its pure rock crawler. This will be a daily driver.