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Tx Firefighter · 09-27-2013, 11:26 AM

I'd think an overdrive trans would be high on the priority list if you keep the big block. I also have a big block dually, 4 speed, and 4.56 gears. It's ridiculously slow with those gears. Strong, yes, but 60 miles per hour is getting wound up. 70 miles per hour is white knuckle hoping the engine doesn't scatter speed.

If you do the Cummins, you're gonna want to re-gear the rearend. Even with an overdrive, 4.56 isn't ideal for a Cummins. I've had 5 Dodge Cummins trucks. They really like 3.54 gears and overdrive the best. Even the Cummins guys with factory 4.10 gears and overdrives often swap the gears for something milder.
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09-27-2013, 11:26 AM	#38
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: 79' C30 Camper Special build thoughts I'd think an overdrive trans would be high on the priority list if you keep the big block. I also have a big block dually, 4 speed, and 4.56 gears. It's ridiculously slow with those gears. Strong, yes, but 60 miles per hour is getting wound up. 70 miles per hour is white knuckle hoping the engine doesn't scatter speed. If you do the Cummins, you're gonna want to re-gear the rearend. Even with an overdrive, 4.56 isn't ideal for a Cummins. I've had 5 Dodge Cummins trucks. They really like 3.54 gears and overdrive the best. Even the Cummins guys with factory 4.10 gears and overdrives often swap the gears for something milder. Posted via Mobile Device Posted via Mobile Device