Another R piston question

I read something in an earlier thread, and now even a search won't dig it up for me. I remember something about the valve reliefs on the 250R piston changing at a certain year model. (I know about the valve stem diameter change in 08) I know that everyone says to use an 08 R piston for 13.1 comp. Will this piston work with both an 07 R head and an 04 X head? My 04 is due for a rebuild. I intend to buy an 07 R head and install the R piston, but would like to rebuild the X head also, so that I always have a spare to just bolt on. Will these two heads both work fine with the 08 R piston?

should work. you can/should always double check after putting it together, but before starting it up :bonk:

I had an 06X head and it worked....then I got an 07R head and it works....

I think you may be refering to different head gasket thickness. As I recall the early X head gasket was very thin and could cause some interference issues with R pistons. Ramsey's site has the info on that.

Pretty sure I run 07' R head with 08' R piston (06'R cam). No problems. I have to look at my receipts when I get home to make sure though.

Edited by jfgjr

BTW just go with the thicker head gasket and you are good to go with any R piston.

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