Pin height is the same on both pistons,the kit pistons are approx 1/4 in taller on the ring end,which is why you need the spacer plate.The pistons in the kit are made for the 800 block. They are made(with all things being equal and in good shape) to slip right into the cylinders. The pin height is also lowered to reduce rock compared to the factory pistons. As far as I know the 700's never had the issues of undersized pistons and pin height too high like the 800's do.