Tranny Swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

85/Silverado · 11-10-2016, 12:23 PM

I took my truck to a Tranny shop to have the pan gasket changed to stop a leak TH350. There were a bunch of chunks of metal and half a washer in the pan, the guy said he couldn't see where it had come from. He said he would guess the Torque Converter is coming apart. I ask what he would charge to buy and build a 700R4 with a B&M shift kit and complete install with a hydraulic lockup converter, he said $1500.oo out the door. Sound Good?

Also I can't get my 383 stroker to get past 130 degrees with my a/c running too. I have aluminum radiator with dual elec. fans.. Should I change my thermostat?

TrailerTrash · 11-10-2016, 07:06 PM

what thermostat do you have now? do the electric fans run all the time? or only when they need to/when the AC is on?

Matt Man · 11-10-2016, 08:07 PM

I would pay 1500 for a 700r4 installed for my truck. Sounds like a great deal to me.

Jaysonb · 11-10-2016, 08:16 PM

I think that if $1500 includes everything, that seems like a good deal.

85/Silverado · 11-10-2016, 11:05 PM

Quote:

Originally Posted by TrailerTrash

what thermostat do you have now? do the electric fans run all the time? or only when they need to/when the AC is on?

The one on the left runs all the time, the other runs with AC only, I have a 195 thermo in it now.

Oldriginal86 · 11-10-2016, 11:18 PM

I paid $1500 to have a 700r4 pulled out, rebuilt and installed. That's a good deal. What's your axle ratio?

85/Silverado · 11-11-2016, 10:47 AM

Quote:

Originally Posted by Oldriginal86

I paid $1500 to have a 700r4 pulled out, rebuilt and installed. That's a good deal. What's your axle ratio?

I have no idea the truck still has the stock 10 bolt in it. The truck came with the 305 motor and th350 tranny.

KrazyRay · 11-11-2016, 10:49 AM

I believe the 700 takes a different driveline than the th350.

TrailerTrash · 11-11-2016, 06:45 PM

Quote:

Originally Posted by 85/Silverado

The one on the left runs all the time

that is probably why the engine doesnt stay/get warm.

Oldriginal86 · 11-11-2016, 09:00 PM

The reason I ask is with the overdrive of the 700, the engine may be lugging in top gear on the highway and your fuel mileage may be worse. My '86 with a 700 has 3:42 ratio.

Speeding Dakota · 11-15-2016, 09:46 PM

Quote:

Originally Posted by 85/Silverado

I have no idea the truck still has the stock 10 bolt in it. The truck came with the 305 motor and th350 tranny.

If you still have your build sheet in the glove box look for one of these codes to determine your gear ratio (if it is still the original rear)

GT4 - 3.73 Rear Axle Gear Ratio
GT5 - 4.10 Rear Axle Gear Ratio
HC2 - 2.76 Rear Axle Gear Ratio
HC4 - 4.56 Rear Axle Gear Ratio
HC8 - 3.21 Rear Axle Gear Ratio
HE3 - 3.07 Rear Axle Gear Ratio
HO4 - 4.11 Rear Axle Gear Ratio

85/Silverado · 11-19-2016, 03:38 PM

I found the build sheet taped to the inside of the glove box it says the rear axle is.

Oldriginal86 · 11-19-2016, 09:33 PM

With a 2.73 ratio your engine rpms are going to be way low at hiway speed. Might want to stick with the th350 trans.

11-10-2016, 12:23 PM	#1
85/Silverado Registered User Join Date: Nov 2011 Location: Port St. Joe Fl. Posts: 491	Tranny Swap I took my truck to a Tranny shop to have the pan gasket changed to stop a leak TH350. There were a bunch of chunks of metal and half a washer in the pan, the guy said he couldn't see where it had come from. He said he would guess the Torque Converter is coming apart. I ask what he would charge to buy and build a 700R4 with a B&M shift kit and complete install with a hydraulic lockup converter, he said $1500.oo out the door. Sound Good? Also I can't get my 383 stroker to get past 130 degrees with my a/c running too. I have aluminum radiator with dual elec. fans.. Should I change my thermostat? Attached Images

11-10-2016, 07:06 PM	#2
TrailerTrash Registered User Join Date: Jun 2015 Location: PA Posts: 441	Re: Tranny Swap what thermostat do you have now? do the electric fans run all the time? or only when they need to/when the AC is on? __________________ - When the Reaper makes his deal, trust in your steel - '77 C10 350/350 2/4 drop and a mild street engine

11-10-2016, 08:07 PM	#3
Matt Man Registered User Join Date: Oct 2009 Location: Buhl, Idaho Posts: 1,438	Re: Tranny Swap I would pay 1500 for a 700r4 installed for my truck. Sounds like a great deal to me. __________________ 86 c30 crew cab dually 454/400 4/6 drop SOLD 1-8-11 1981 chevy K10 short Bed Scottsdale SOLD 10-26-2020 67 GMC Stepside Straight six/3 on the tree "The Peach" 2020 Silverado Double Cab LT Z71 5.3 8 speed Daily Driver K10 build http://67-72chevytrucks.com/vboard/s...d.php?t=671934 The Peach build http://67-72chevytrucks.com/vboard/s...d.php?t=733903

11-10-2016, 08:16 PM	#4
Jaysonb Registered User Join Date: May 2009 Location: Good Thunder Mn. Posts: 955	Re: Tranny Swap I think that if $1500 includes everything, that seems like a good deal.

11-10-2016, 11:18 PM	#6
Oldriginal86 Registered User Join Date: Apr 2013 Location: Pasadena, Maryland Posts: 160	Re: Tranny Swap I paid $1500 to have a 700r4 pulled out, rebuilt and installed. That's a good deal. What's your axle ratio?

11-11-2016, 10:49 AM	#8
KrazyRay Registered User Join Date: Jun 2009 Location: Oroville, CA Posts: 4,827	Re: Tranny Swap I believe the 700 takes a different driveline than the th350.

11-11-2016, 09:00 PM	#10
Oldriginal86 Registered User Join Date: Apr 2013 Location: Pasadena, Maryland Posts: 160	Re: Tranny Swap The reason I ask is with the overdrive of the 700, the engine may be lugging in top gear on the highway and your fuel mileage may be worse. My '86 with a 700 has 3:42 ratio.

11-19-2016, 03:38 PM	#12
85/Silverado Registered User Join Date: Nov 2011 Location: Port St. Joe Fl. Posts: 491	Re: Tranny Swap I found the build sheet taped to the inside of the glove box it says the rear axle is. Attached Images Last edited by 85/Silverado; 11-19-2016 at 03:48 PM.

11-19-2016, 09:33 PM	#13
Oldriginal86 Registered User Join Date: Apr 2013 Location: Pasadena, Maryland Posts: 160	Re: Tranny Swap With a 2.73 ratio your engine rpms are going to be way low at hiway speed. Might want to stick with the th350 trans.

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