440 Question?

[FBRacing76]

Im thinking about putting the 440 Big Bore in 400ex with 12.5:1 compression piston. Can anyone tell me if I would have to run racing gas. I mostly trail ride an do some small races so I dont wanna run on racing fuel. Could someone please let me know soon! Thanks!

[redgrizz]

pretty sure with that high compression u do

[Chanman420q]

if its a weisco piston u may not have too... but any other piston ( je or ross ) u definitly will. To be safe run a 10.8:1 compression. 11:1 is the limit on pump gas. Sometimes u have to run 50/50. But if you definitly dont want anything to do with race gas get a 10.8:1