The stock parts are not interchangable, the 520 cylinder has a longer stroke than the 400 crank, so it wont work.
Although, there are a few people on hear punching out there 400's to 450's.
Might want to do a search in this forum and find the thread, from there you will contact the person invloved via IM or e-mail.
The stock parts are interchangeable. You can use a 520 cylinder & piston with a 400 crank!
I just converted my 400 into a 540 ( KTM hard equipment ) but I had to install a 520 crankshaft. If it turns out I don't like that combination, I'm going to try that 454 combination by putting in the 400 crank. Sooo.... stay tuned:)
Stroker. With a 520 crank installed, you bsically have a 520, but with the 400 crank (64mm stroke) in a 520 cylinder that has a stroke of (72mm),....... Sounds like some major machining going on!!??:eek:
I wouldn't replace the rod because I want the stroke of the 400.( they are different length rods ) But after thinking about it:think I would have to have a piston made. I checked the pin location on the 400 ( vs ) 520/540 and the 400 is 4mm lower ( measuring from the top of the piston to the center of the pin )
I was wondering about the pin locations but just figured that if they made two diff length rods that they would leave the pin locations the same between the two pistons. Would have made the whole thing a lot easier huh?