arter a few / decided to leave factory studs in,bought metric bolts,ground a flat spots on washers to match with the flange welds,installed lock washers then new metric nuts,worked great,raised the nut just over the sides of the welds. Got mapping from echo also.Had it out once before track speed was 39-45 mph depending on snow,hope to be 45-48 mph or a little higher??????????????. thanx for the reply.what clutch set up r u running