4L60E in place of my 700R in '70 pickup - The 1947 - Present Chevrolet & GMC Truck Message Board Network

diggerbob · 05-17-2014, 04:29 PM

I am thinking about getting a new transmission built for my truck. Right now I have a 1984 vintage 700R. It is a used transmission so I am looking to get something a little updated. I was thinking about finding a core from a 87-92 and having it built but my buddy suggested that I let him build me a 4L60E instead. The idea is to use a TCM from a diesel equipped truck from 1991 to 1997 to run it. Any suggestions on an adapter to make my mechanical speedo work or will I need to swap out my speedo for an electric one?

Bigdav160 · 05-17-2014, 06:15 PM

The problem with your plan is GM diesels had 4L80e transmissions behind them not 4L60e.

IIRC, the electronics are not interchangeable.

There are stand alone aftermarket controllers and I've read about using GM computers as stand alone controllers.

Why don't don't just have your 700 rebuilt and upgraded? It wouldn't worry me a bit that it is an '84 model. People just make a bigger deal out of it than it really is.

mgchevyparts · 05-17-2014, 06:29 PM

I'd keep the 700

Carmen Black · 05-17-2014, 09:28 PM

I have been thinking of doing the same as a first step toward my LS swap. Ended up deciding against it for now.

You can get a box that will convert the electrical signal of the transmission to the mechanical system of the speedometer, but they run about $300.

Electronic transmissions also need a TPS (throttle position sensor). Holley makes one you can add to your carb for another $100.

I don't know much about used TCM's, but if it doesn't work and you have to buy a stand alone controller, that is another $600.

I decided to delay mine until I do the full swap. You really have to be committed to get an electronic transmission into one of these trucks, where the 700R4 will just drop right back in.

**Boog** · 05-17-2014, 09:48 PM

The last few days I've been thinking about the E trans in my wrecked 97 GMC. It had a lot of miles on it but it worked perfect when wrecked. I have been looking at stand alone controllers and see they run from 600 to around 1300 and you still need a converter at 300 to run the speedo.
I just can't see spending that much money on a used transmission just to get it to work. The money might be better spent beefing up an older 700R4.

dirtyjim · 05-18-2014, 07:11 AM

unless your buddy has a stash of those diesel pcm's good luck on finding one. the junkyards were picked clean years ago, and if he dose have one it will need to be reflashed to shift correctly on a gas engine.

66skylarkpost · 05-18-2014, 08:01 AM

[QUOTE=diggerbob;6677648] Right now I have a 1984 vintage 700R. It is a used transmission so I am looking to get something a little updated. I was thinking about finding a core from a 87-92 and having it built/QUOTE]

yeah , do that .ur current 84 model is not worth messing with. and the 4l60e will just be a electrical version on a later 700 , more work.

**WIDESIDE72** · 05-18-2014, 01:10 PM

The early 700's can be updated to include all of the features of the later 700's. i would avoid the 4l60e like the plague unless i was also swapping the matching electronically controlled engine at the same time. As mentioned above all of the expense to get one to function is not worth it.

05-17-2014, 04:29 PM	#1
diggerbob Registered User Join Date: Mar 2005 Location: Bartlett, TN (near Memphis) Posts: 202	4L60E in place of my 700R in '70 pickup I am thinking about getting a new transmission built for my truck. Right now I have a 1984 vintage 700R. It is a used transmission so I am looking to get something a little updated. I was thinking about finding a core from a 87-92 and having it built but my buddy suggested that I let him build me a 4L60E instead. The idea is to use a TCM from a diesel equipped truck from 1991 to 1997 to run it. Any suggestions on an adapter to make my mechanical speedo work or will I need to swap out my speedo for an electric one? Last edited by diggerbob; 05-18-2014 at 09:00 AM.

05-17-2014, 06:15 PM	#2
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: 4L60E in place of my 700R in '70 pickup The problem with your plan is GM diesels had 4L80e transmissions behind them not 4L60e. IIRC, the electronics are not interchangeable. There are stand alone aftermarket controllers and I've read about using GM computers as stand alone controllers. Why don't don't just have your 700 rebuilt and upgraded? It wouldn't worry me a bit that it is an '84 model. People just make a bigger deal out of it than it really is. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

05-17-2014, 06:29 PM	#3
mgchevyparts Registered User Join Date: Feb 2013 Location: Upland, Calif Posts: 698	Re: 4L60E in place of my 700R in '70 pickup I'd keep the 700 __________________ 1957 CHEVY 1/2 TON SHORT BED 1940 FORD 1/2 TON SHORT BED

05-17-2014, 09:28 PM	#4
Carmen Black Registered User Join Date: Aug 2013 Location: Cary, NC Posts: 60	Re: 4L60E in place of my 700R in '70 pickup I have been thinking of doing the same as a first step toward my LS swap. Ended up deciding against it for now. You can get a box that will convert the electrical signal of the transmission to the mechanical system of the speedometer, but they run about $300. Electronic transmissions also need a TPS (throttle position sensor). Holley makes one you can add to your carb for another $100. I don't know much about used TCM's, but if it doesn't work and you have to buy a stand alone controller, that is another $600. I decided to delay mine until I do the full swap. You really have to be committed to get an electronic transmission into one of these trucks, where the 700R4 will just drop right back in.

05-17-2014, 09:48 PM	#5
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,513	Re: 4L60E in place of my 700R in '70 pickup The last few days I've been thinking about the E trans in my wrecked 97 GMC. It had a lot of miles on it but it worked perfect when wrecked. I have been looking at stand alone controllers and see they run from 600 to around 1300 and you still need a converter at 300 to run the speedo. I just can't see spending that much money on a used transmission just to get it to work. The money might be better spent beefing up an older 700R4. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

05-18-2014, 07:11 AM	#6
dirtyjim Registered User Join Date: Feb 2013 Location: alvin, texas Posts: 622	Re: 4L60E in place of my 700R in '70 pickup unless your buddy has a stash of those diesel pcm's good luck on finding one. the junkyards were picked clean years ago, and if he dose have one it will need to be reflashed to shift correctly on a gas engine. __________________ 1967 C10 lwb two tone, 305 & rat fink style floor shifted 700r4, 20" steelies 2004 2500HD utility bed aka Brutus

05-18-2014, 08:01 AM	#7
66skylarkpost Registered User Join Date: Mar 2006 Location: kearney,nebraska Posts: 443	Re: 4L60E in place of my 700R in '70 pickup [QUOTE=diggerbob;6677648] Right now I have a 1984 vintage 700R. It is a used transmission so I am looking to get something a little updated. I was thinking about finding a core from a 87-92 and having it built/QUOTE] yeah , do that .ur current 84 model is not worth messing with. and the 4l60e will just be a electrical version on a later 700 , more work. __________________ '70 k-10 longbox- mid 70's drivetrain 350/350 487x heads 10.1:1 flowmasters ,35's 3.73's auburn posi ,rear shackle flip. '72 short stepside U.S. forestry truck, '73 455 buick,400 turbo,dropped 2"-4 1/4" ,3.07 posi,:'89 silverado 1500 ,OK truck ,5.7 holley tbi ,trick 700r4 3.07 auburn posi ,and my '66 skylark ,'73 centurion and my '84 monte carlo imca stock car

05-18-2014, 01:10 PM	#8
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,500	Re: 4L60E in place of my 700R in '70 pickup The early 700's can be updated to include all of the features of the later 700's. i would avoid the 4l60e like the plague unless i was also swapping the matching electronically controlled engine at the same time. As mentioned above all of the expense to get one to function is not worth it.



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