When it came time to assemble my 6.0L stroker rotating assembly, I decided to use a set of Mahle pistons because these particular stroker pistons had the slight dish that would work to keep the compression lower in case we decided to use a blower later on in the test cycle. These pistons use a very thin 1.5 to 1.5-3mm ring package. I’ve built several street engines in the past, but this was the first time I’d ever tried assembling a 3mm oil ring package. Because the connecting rod and stroke package ended up putting the wristpin into the oil ring, this requires the use of an oil ring spacer to create a floor for the oil ring where the wristpin intrudes. I installed the spacer and then tried unsuccessfully for several minutes to install the oil ring pack on the first piston. What I discovered (after some help from machinist/engine builder Jim Grubbs) was that the entire package can easily push out of the oil ring groove when the package is this small. It requires installing the expander first, then carefully installing the top steel ring and finally the bottom ring all while keeping the oil ring package centered around the piston. If I forced the ring package all the way over to one side, the steel rings can easily slide out of the groove and you must then start all over. Once I learned that little trick, I managed to get all eight piston and rings assembled without too much difficulty.