Tranny/Posi combo - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GMC_Aaron · 07-11-2002, 03:46 PM

I have a 1972 GMC Super Custom truck that is basically stock and I want to put in a tranny with over drive. I would also like to put in a posi rear end. I have TH400 now, but I want overdrive because I go on some long trips every now and then and I would like to have overdrive. Posi can speak for itself. What would be a good setup? Any ideas would be helpful.

slam33 · 07-11-2002, 03:53 PM

Big or small block ? You can go for an all in one like a 700r4 but I'm not sure how it would handle a BB, maybe yes maybe not so yes. Or you can go with an aftermarket add on like a Gear Vendor, with a BB yes it can handle it. Your going to be looking for a non- computer controled unit.

68 with 350 TPI · 07-11-2002, 04:05 PM

what kinda engine do you have?

With a vette servo and a hardend sunshell ,pump mod,and shift kit on a newer 700r4 can take up to about 500 hp without slicks pretty easy.

But it would be wise to get a gear vendors under/overdrive unit and bolt it up to your th400.

Those things can handle 1,200 hp out of the box!

Either way it is going to cost a little to get a good overdrive unless you have a good hookup with a local bone yard/trans shop.

Mike C · 07-11-2002, 06:13 PM

TH700 and 4.10 gears if you are running a 30" tire (like 265 75 16) or 3.73 if runnin a 28" tire. The 700 should be fine as a new Vortec 350 makes as much torque as a mostly stock truck 402. Figure on spending at LEAST $1000 dollars and shop around for a rebuilder with a GOOD rep for 700's as they are more finicky than a TH350/400. The gear Vendors will set you back $2000 in addition to the fact your 400 probably could use a rebuild anyways.

GMC_Aaron · 07-11-2002, 08:23 PM

I have a small block 350.

Custom 68 · 07-11-2002, 11:09 PM

What the heck are you guys talking about? What is this thing you bolt to your 400 turbo to make it an overdrive? Is there a site with more info on them? or am I misunderstanding what you mean.
Thanks
Well ok I guess I should have looked around before asking. I had just never heard of them. Here is a link I hope
http://www.findarticles.com/cf_offrd.../article.jhtml

frogsmakr · 07-11-2002, 11:27 PM

try www.gearvendors.com

07-11-2002, 03:46 PM	#1
GMC_Aaron Registered User Join Date: Jul 2002 Location: Ventura, Ca. Posts: 87	Tranny/Posi combo I have a 1972 GMC Super Custom truck that is basically stock and I want to put in a tranny with over drive. I would also like to put in a posi rear end. I have TH400 now, but I want overdrive because I go on some long trips every now and then and I would like to have overdrive. Posi can speak for itself. What would be a good setup? Any ideas would be helpful. __________________ Aaron Ventura, Ca. 1972 GMC Super Custom SB350/TH400

07-11-2002, 03:53 PM	#2
slam33 Registered User Join Date: Aug 2001 Location: Long Beach, Ca Posts: 1,432	Big or small block ? You can go for an all in one like a 700r4 but I'm not sure how it would handle a BB, maybe yes maybe not so yes. Or you can go with an aftermarket add on like a Gear Vendor, with a BB yes it can handle it. Your going to be looking for a non- computer controled unit. __________________ 71 LWB 350/350still working on it but it's going tp be sweet. www.geocities.com/stevemau/slam33page.html " TARGET=_blank>http://www.geocities.com/stevemau/slam33page.html?1004806705410 </A>

07-11-2002, 04:05 PM	#3
68 with 350 TPI Registered User Join Date: May 2002 Location: Wingate NC Posts: 456	what kinda engine do you have? With a vette servo and a hardend sunshell ,pump mod,and shift kit on a newer 700r4 can take up to about 500 hp without slicks pretty easy. But it would be wise to get a gear vendors under/overdrive unit and bolt it up to your th400. Those things can handle 1,200 hp out of the box! Either way it is going to cost a little to get a good overdrive unless you have a good hookup with a local bone yard/trans shop. __________________ Life is good with a 6-71 supercharged 355 in a 72 camaro

07-11-2002, 06:13 PM	#4
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	TH700 and 4.10 gears if you are running a 30" tire (like 265 75 16) or 3.73 if runnin a 28" tire. The 700 should be fine as a new Vortec 350 makes as much torque as a mostly stock truck 402. Figure on spending at LEAST $1000 dollars and shop around for a rebuilder with a GOOD rep for 700's as they are more finicky than a TH350/400. The gear Vendors will set you back $2000 in addition to the fact your 400 probably could use a rebuild anyways. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

07-11-2002, 08:23 PM	#5
GMC_Aaron Registered User Join Date: Jul 2002 Location: Ventura, Ca. Posts: 87	I have a small block 350. __________________ Aaron Ventura, Ca. 1972 GMC Super Custom SB350/TH400

07-11-2002, 11:09 PM	#6
Custom 68 Registered User Join Date: Nov 2001 Location: Springfield, MO Posts: 2,939	gear vendors What the heck are you guys talking about? What is this thing you bolt to your 400 turbo to make it an overdrive? Is there a site with more info on them? or am I misunderstanding what you mean. Thanks Well ok I guess I should have looked around before asking. I had just never heard of them. Here is a link I hope http://www.findarticles.com/cf_offrd.../article.jhtml __________________ Dave 1968 Custom Chevy with turbo charged 5.3 gen III 4l80e swap 1967-71 GMC 3/4 ton long step 4x4 (not sure what year exactly?) "A good friend will bail you out of jail...but a true friend will be sitting next to you saying "that was frekin awesome". "If it doesn't fit force it...If it breaks then it needed to be replaced anyway!" Last edited by Custom 68; 07-11-2002 at 11:16 PM.

07-11-2002, 11:27 PM	#7
frogsmakr Registered User Join Date: Feb 2000 Location: Sherwood AR Posts: 553	try www.gearvendors.com



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