As I hear it, you are subbposed to use the octain in occordance with your compression, 8.5:1 compression=85 octane gas. Since the falttys came with about 6.5:1 compression the cheapest would be fine, unless you upped the compression and timming (alot) then the higher octane would be wise.
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.