Has anyone run into this problem before, I have a 67 camaro, 355 sbc, muncie m20 4 speed, hurst competion plus, 373 posi. There is a bad vibration in the shifter handle, starting around 50 mph and geting worse from there on up. I have new mounts, have changed driveshafts, new u-joints, new rear bushing in tailshaft housing, new clutch and plate. The vibration ends when I push in the clutch, has anyone run into something like a bent mainshaft in a muncie? I welcome any ideas on this problem.