i have a set of C1AE's that that were milled down from the 76 range to 69cc. machine shop didnt want to take it much further. it could have went lower but wasnt nessecary for what i wanted. e-85 would be an intresting build, id shoot for 12:1 if i were you. buddy of mine has a 500 c*!#y motor that dynod at 635ftlbs and 428hp to the wheels. with only a cam, 12:1, no head work(stock iron), no headers, aftermarket intake, running e85. a word of warning get a carb that is setup for it. he is battling issues with his. he cant find any bigger jets for it, but it still wants more. he may have other tunning issues with it though. he also says its a bitch to start especially in the cold. takes alot of fuel to make it run.
