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GreyFox · 05-28-2019, 10:53 AM

Changes made on my is I kept the Eaton axle and changed out the diff to a '72 4:10 it was a 4:56 rear.

I still have the sm420 in my truck and have considered moving to the sm465 but I don't know if I can get the part that would allow me to fix the speedo setup in the transmission. I may have to figure out the fix by using an external increase method.

See the ebay search here: https://www.ebay.com/itm/GM-and-Dodg...0AAOSw95lbKRPH

05-28-2019, 10:53 AM	#5
GreyFox Registered User Join Date: Dec 2017 Location: Forest Grove OR Posts: 15	Re: Original tire size information Changes made on my is I kept the Eaton axle and changed out the diff to a '72 4:10 it was a 4:56 rear. I still have the sm420 in my truck and have considered moving to the sm465 but I don't know if I can get the part that would allow me to fix the speedo setup in the transmission. I may have to figure out the fix by using an external increase method. See the ebay search here: https://www.ebay.com/itm/GM-and-Dodg...0AAOSw95lbKRPH Last edited by GreyFox; 05-28-2019 at 11:02 AM.