I need to rebuild my 1970 CB450. Compression check reads 90 psi on the left cylinder and 100 psi on the right cylinder. I might just try replacing the rings with standard size replacements as a cheap way to get back on the road before winter hits and then do a proper rebuild when its too cold to ride. Ebay is the only place where I can find rings, and every once in while i can find nos pistons on there but they're way to expensive. Wiseco is the only other place were i can find pistons but they want $180 a piece! This is a badass show quality cafe racer that i've spent all year building and i just want to be able to show it off at work before the riding season is over.