The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 454 Dually with 4.56 rear diff, what auto trans to use

Puglia10 · 02-02-2022, 01:08 PM

Was just searching for a similar thread before I made my own.

Im not planning on actually towing/working the truck at all, and I dont really care about gas- I'd just like to be able to do highway speeds around here (70-75) without sounding like the 454 is gonna blow.

Not sure of my rear end gears (no glove box code) but its a 1979 GMC crew cab dually camper special with the 454 and 3 speed auto.

I assume changing my gear ratio is the best way to go to get more more highway comfort?

02-02-2022, 01:08 PM	#15
Puglia10 Registered User Join Date: Apr 2009 Location: Boston MA Posts: 387	Re: 454 Dually with 4.56 rear diff, what auto trans to use Was just searching for a similar thread before I made my own. Im not planning on actually towing/working the truck at all, and I dont really care about gas- I'd just like to be able to do highway speeds around here (70-75) without sounding like the 454 is gonna blow. Not sure of my rear end gears (no glove box code) but its a 1979 GMC crew cab dually camper special with the 454 and 3 speed auto. I assume changing my gear ratio is the best way to go to get more more highway comfort? __________________ 1979 c30 3+3 dually 1946 GMC