I'm building a 82 RM 125 to do some vintage racing and looking to get some more power out of it. I plan on some cylinder work, boyesen reeds and bringing the piston to head squish clearance down some since stock it is .080". I also have a 35mm PWK air striker I may try. This year head has the full hemi open design with no step and I'm not familiar with this design. As for the exhaust I'm only able to find DG available pipes, so the question is, is the DG pipe any good for these older RM's or just better to run the stock pipe ? Any do's and don'ts on engine modifications would be appreciated !!!!