The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 3 speed overdrive with an HEI distributor

D'Monsta · 11-12-2021, 10:03 AM

Thanks for all this great info from all of you fellas.. My '66 GMC with 250 has an HEI distributor now. The original SM 318 is popping out of 3rd and vibrating to the point that the windows and heater diverter are rattling so loud I can't hear the radio!.. I have 2 of the SM-319 transmissions with OD so my plan is to clean one up real good, inside and out, and install it.. If it passes the 'gears good' test, I'll activate the OD functions.. Will post updates here..

11-12-2021, 10:03 AM	#35
D'Monsta Registered User Join Date: Aug 2020 Location: Charlotte Posts: 48	Re: 3 speed overdrive with an HEI distributor Thanks for all this great info from all of you fellas.. My '66 GMC with 250 has an HEI distributor now. The original SM 318 is popping out of 3rd and vibrating to the point that the windows and heater diverter are rattling so loud I can't hear the radio!.. I have 2 of the SM-319 transmissions with OD so my plan is to clean one up real good, inside and out, and install it.. If it passes the 'gears good' test, I'll activate the OD functions.. Will post updates here..