I recently sent a 35 Stunt to Larry Foster for rework and am very happy with the results. Among other things for only $30, mounting lugs squared, venturi cleaned up, head and back plate scews replaced with hex head screws, disassembled, fit of internal parts checked, reassembled with new crank, stuffer backplate, and hemi head (I supplied parts which I had already purchased from Aeroproducts). I think he charges $40 if he has to rework the stock crank. Any parts you don't have he can supply at a very reasonable price as well, as can Randy Smith at Aeroproducts.
cheers,
Ken