Hello, my 426 ex is about dead (severe metallic clanking...sounds like the timing chain and I've read on here that the guides are known to break). ANYWAYS...while it is apart i am going to go ahead and put the 440 kit in. My question is...will i have to have the cylinder machined again (had it done once to put the 426 sleeve in) or will the 440 sleeve fit into the machined cylinder in which the 426 sleeve is now? I already have a hotcam, revbox, no airbox lid and jetting. It ran awesome until it died. Thanks in advance.

 

anyone???

 

I would think it would depend on the thickness of the sleeve you had installed when you did the 426.
You may have to take it back into the same shop that did your 426 so they can determine if it can be bored for the 440.
You can also stay with the 426 piston size and install a stroker crank to achieve a 440.