I have a question regarding this type of change , will you have to use primary and secondary clutches off 670 for use in the 500 s place ?I"m thinking of transplanting my formula 500 with this 670 out of mxz for some big block power [ making a sleeper] . Or will a 670 with original clutch work, leaving the 500 secondary clutch on the sled work? Every other part is traded off one machine[mxz670] to the other [formula500] so I guess it will be no problems. I"m hopeing to target someone that has done this job before for advise! ???