72 3/4 ton trans swap or no?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

troyhubers · 08-09-2004, 09:50 PM

I have a 3/4 72 chevy longbed. 350/350. with 4.11 rearend. I am just getting her back on the road and need to know if i should put in a different transmission in the future. I will be doing some pulling with this truck. Small tractors locally. Some people have told me to get an overdrive auto transmission and it should help with MPG. I only get 11 mpg now, and i know it won't get drastically better, but woud it be worth it to switch to an overdrive auto. and if so what transmission, or should i go with a manuel. Thanks.

Troy L. Hubers

Longhorn Man · 08-09-2004, 10:26 PM

Welcome to the board from central Ohio...where you at in the world?

If you'll be towing, I wouldn't even consider an overdrive. Maybe a Th400, but not untill the Th350 died.

troyhubers · 08-09-2004, 10:53 PM

From Pantego, NC East coast.

Robert1970C20rstbukt · 08-09-2004, 10:58 PM

I'm running 4.11's with a th400 in mine and it has no problems pulling stuff. The th400 is a better, heavy duty transmission compared to a th350 is what I was told.

Tx Firefighter · 08-09-2004, 11:06 PM

With 4:11 gears and a 3/4 ton, you're never going to get too much better mileage than you're getting now. I've never been able to exceed 14 in a 1/2 ton 3:73 with overdrive.

For pulling, the non overdrive transmissions are much cheaper. An overdrive fortified enough to pull much will cost you way more than it will ever recoup with mileage gains.

08-09-2004, 09:50 PM	#1
troyhubers Registered User Join Date: Aug 2004 Posts: 6	72 3/4 ton trans swap or no?? I have a 3/4 72 chevy longbed. 350/350. with 4.11 rearend. I am just getting her back on the road and need to know if i should put in a different transmission in the future. I will be doing some pulling with this truck. Small tractors locally. Some people have told me to get an overdrive auto transmission and it should help with MPG. I only get 11 mpg now, and i know it won't get drastically better, but woud it be worth it to switch to an overdrive auto. and if so what transmission, or should i go with a manuel. Thanks. Troy L. Hubers

08-09-2004, 10:58 PM	#4
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	I'm running 4.11's with a th400 in mine and it has no problems pulling stuff. The th400 is a better, heavy duty transmission compared to a th350 is what I was told. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

08-09-2004, 11:06 PM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	With 4:11 gears and a 3/4 ton, you're never going to get too much better mileage than you're getting now. I've never been able to exceed 14 in a 1/2 ton 3:73 with overdrive. For pulling, the non overdrive transmissions are much cheaper. An overdrive fortified enough to pull much will cost you way more than it will ever recoup with mileage gains. __________________ I'm on the Instagram- @Gearhead_Kevin

08-09-2004, 10:26 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Welcome to the board from central Ohio...where you at in the world? If you'll be towing, I wouldn't even consider an overdrive. Maybe a Th400, but not untill the Th350 died.

08-09-2004, 10:53 PM	#3
troyhubers Registered User Join Date: Aug 2004 Posts: 6	From Pantego, NC East coast.



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