Transmission upgrade question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bm* · 02-08-2010, 12:59 PM

My 1986 4x4, ¾ ton drive train has the 3 speed auto, from what I have been reading, that was the end all be all auto transmission. That would probably be great if it was 1987 to day and the speed limit was 55. What other options do I have for an overdrive transmission? I have the stock 350 engine and will be going to run 36 or 37’s. Any input would be appreciated.

**old Rusty C10** · 02-08-2010, 02:41 PM

you could put in a 700R4 easy enough there is some kind of a controller you have to buy for the lockup and those are sold aftermarket

*SMiller* · 02-08-2010, 03:30 PM

Keep the TH400 you have now and install a gear vendors over drive (google search this) or install a built 4L80E with stand alone controls. You could also go the hard way and install a 8.1\Allison combo, good mileage and power.

The nice part about any other trans. is a low first gear to get going and the tall over drive to cruise in, the 400 has pretty crappy gear ratios, but we love it! Man up and keep putting gas in it, your mileage will be complete crap with 37's anyways, might as well have a trans that will take the abuse!

02-08-2010, 12:59 PM	#1
bm* Registered User Join Date: Feb 2010 Location: haslet, tx Posts: 24	Transmission upgrade question My 1986 4x4, ¾ ton drive train has the 3 speed auto, from what I have been reading, that was the end all be all auto transmission. That would probably be great if it was 1987 to day and the speed limit was 55. What other options do I have for an overdrive transmission? I have the stock 350 engine and will be going to run 36 or 37’s. Any input would be appreciated.

02-08-2010, 02:41 PM	#2
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	Re: Transmission upgrade question you could put in a 700R4 easy enough there is some kind of a controller you have to buy for the lockup and those are sold aftermarket __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

02-08-2010, 03:30 PM	#3
SMiller Account Suspended Join Date: Jun 2009 Location: Tipton IN Posts: 81	Re: Transmission upgrade question Keep the TH400 you have now and install a gear vendors over drive (google search this) or install a built 4L80E with stand alone controls. You could also go the hard way and install a 8.1\Allison combo, good mileage and power. The nice part about any other trans. is a low first gear to get going and the tall over drive to cruise in, the 400 has pretty crappy gear ratios, but we love it! Man up and keep putting gas in it, your mileage will be complete crap with 37's anyways, might as well have a trans that will take the abuse!



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