89 Silverado 700r4 to 4l80e swap

[wittensville]

I have an 89 Silverado with a 5.7 tbi and a dying 700r4. I have acquired a 94 2500 with a 5.7 and a 4l80e. I would like to know what parts I would have to change to do a swap.

 

[Nad_Yvalhosert]

You have an entire donor truck, you have all the parts you need: the tranny, cooler lines, wiring harness, ECM, torque converter, (t-case if equipped), output yoke.
Though you might need a conversion u-joint... Moog 447 or equivalent, and depending in wheelbase differences which you didn't mention, there's also driveshaft modification possible

 

[wittensville]

You have an entire donor truck, you have all the parts you need: the tranny, cooler lines, wiring harness, ECM, torque converter, (t-case if equipped), output yoke.
Though you might need a conversion u-joint... Moog 447 or equivalent, and depending in wheelbase differences which you didn't mention, there's also driveshaft modification possible

Thanks, do I have to change the harness under the dash?

 

[Schurkey]

Subscribed.

 

[PlayingWithTBI]

Another option is getting a stand-alone trans controller, pretty expensive though. I haven't done this YET, but have been looking at options.

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[618 Syndicate]

What year of the 80 has the standalone? I know it's a TBI truck but I can never remember the year.
@someotherguy is it 94?

 

[Supercharged111]

Another option is getting a stand-alone trans controller, pretty expensive though. I haven't done this YET, but have been looking at options.

www.summitracing.com/search/part-type/automatic-transmission-controllers/transmission-make/gm

Automatic Transmission Controllers - GM Transmission Make - Free Shipping on Orders Over $109 at Summit Racing

Find Automatic Transmission Controllers GM Transmission Make and get Free Shipping on Orders Over $109 at Summit Racing!

www.summitracing.com

Meh, the stock one works just fine and can be tuned and is on hand. Seems to me the engine harness and PCM ought to be swapped out. The added trans wiring should pass through the firewall on the passenger's side. There is no mention of 2wd 4wd on either the donor or the recipient. If those are different that throws a monkey wrench in the whole thing. How about wheelbases? The driveshaft length will be different between the 2.

 

[PlayingWithTBI]

Meh, the stock one works just fine and can be tuned and is on hand. Seems to me the engine harness and PCM ought to be swapped out

Yeah, and that's why I've been researching it since then, I lose my EBL Flash-II ECM if I do that. Or run both computers in parallel. Just looking at other options...

 

[someotherguy]

What year of the 80 has the standalone? I know it's a TBI truck but I can never remember the year.
@someotherguy is it 94?

Wouldn't it be a pre-electronic injection 6.5td (and 6.2 of course) that just has a standalone transmission controller? In that case it would be 1991-1993 diesels only.

Richard

 

[smdk2500]

Wouldn't it be a pre-electronic injection 6.5td (and 6.2 of course) that just has a standalone transmission controller? In that case it would be 1991-1993 diesels only.

Richard

I think the trucks with 6.2's hat a TH400. But the pre 94 trucks with 6.5 had a standalone controller.