I put a 12:1 engine in a street rod and hated it. Blew two head gaskets. I took the pistons out and milled the domes to about 10.5 I still have to mix in a gallon of 110 race fuel with every tank of pump premium. Bummer.

I think a street six runs best in the 9.0 - 9.2 range, and even at that you will probably need premium fuel to optimize the camshaft and ignition timing.
Good luck.

Last edited by THE FRENCHTOWN FLYER; 11/20/09 01:33 PM.
FORD 300 inline six - THE BEST KEPT SECRET IN DRAG RACING!