I finished gapping my rings and was (trying) to install my pistons--even with a scissors style ring compressor they just wouldn't go in. So I checked my oil expander--it seems its to "big" for the bore--the ring set I got--corresponds to the pistons (SRP pistons JE rings) both 75.5mm. So what was happening is that the expander had no where to flex when it was in the ring groove--so the piston couldn't go in. I called JE and told them this and he says it wouldn't be a problem to trim the ends of the oil expander. The actual metal (flat) oil rings are fine--I have plenty of clearance there. I tried trimming a small amount off of the expander-- I tried to install the pistons again, and they went right in. My question is, when it is necessary to "trim" the ends of the oil expander--should you trim the ends so they butt up like they originally did? Or can I just trim a bit off, and they way they meet up is the way they meet up. If I trim them to make the ends butt up the way they did originally would mean I would have to trim alot of material--I only want to take a little off. I hope I am making this clear--Its kind of hard to explain, thanks.