New Old Stock 25XS Exchange Kit. Mercury Part No. 872-9533A 8. This kit contains a new block, crankcase, port covers, exhust cover, gaskets, pistons, with rings and pins, miscellaeous hardware including the instructions. Looks like piston pin bearings are missing as is the themostat cover, could be a couple other parts missing also. Shipping charges will depend on destination, we only charges what it costs us to ship the item.