Does anyone know of a good scouce for Corvair tach repair ? went thru 3 on sun trying to find one that works properly. I think I messed up the one that worked closest to accurate. It read 500 rpm with motor off,but I think it may have been correct above that (2700 rpm @ 60 mph with a 3:27diff) Thanks Russ Davis Blue Chip Mach CORSA CVCC