I swapped my factory rocker boxes out today for these TP pro vent rocker boxes. They are nice! Super chrome finish. It turned out to be an all day job, a lot of time looking for tools that I could squeeze into no spaces. Couldn't use a torque wrench on all the bolts because of clearance between frame and engine. They are a complete change from the Harley boxes. The one big change is that the rocker shaft stanchons are milled into the box, not a seperate bolt on like Harleys, and they use ''O'' ring gaskets around the perimeter and the decompression chimney and the screws that hold the top cover on.