411 swap

[Eric1964]

I am swapping motors and we are getting to that point in the build to start redoing the harness ..7It is a 8.1 out of a 2000 3500hd 2wd going into a 97 4x4 burban that had a 7.4 in it

My questions are...
I believe im taking the electronic throttle out of the 2000 to put in the 97.......
what do I do for the harness for the electric throttle?
Fuel lines look different not exactly sure what to do there
How do we wire in the 4x4?
Fyi we are using the 7.4 harness and repining it to the 411 processor to run the 8.1
should I worry about having it tuned being I'm using the computer that came with the 8.1
Should I have to worry about a passlock

Any answers would be greatly appreciated

 

[Supercharged111]

Your 4lo won't work right without a 4x4 PCM. Repinning the PCM connectors is plenty easy, but you're going to have to add the coils to the 7.4 harness and change out plugs that don't match on the engine side. Probably still easier than butchering the 800 harness to fit the 4x4 400. I'd just rock the cable throttle, I don't know that a pedal from a newer truck bolts in/packages well in a 400. Plus you're not going to have traction control.

 

[454cid]

Your 4lo won't work right without a 4x4 PCM. Repinning the PCM connectors is plenty easy, but you're going to have to add the coils to the 7.4 harness and change out plugs that don't match on the engine side. Probably still easier than butchering the 800 harness to fit the 4x4 400. I'd just rock the cable throttle, I don't know that a pedal from a newer truck bolts in/packages well in a 400. Plus you're not going to have traction control.

A 2000 3500HD is a GMT-400. Although, I am a bit confused as to why it has an 8.1L.... didn't think that happened until 2001. 2000 should be the last year for the 454.

 

[Supercharged111]

He doesn't have an 800 harness. A 2000 3500HD is a GMT-400. Although, I am a bit confused as to why it has an 8.1L.... didn't think that happened until 2001. 2000 should be the last year for the 454.

Oh, derr, good catch on it being a 400. So yes OP grab the throttle pedal. It's going to plug into the dash harness though like the 6.5, so you'll either need to add that portion of wiring to yours or yank both dashes to swap the harnesses, at which point you'd still need to somehow add that wiring under the hood to the PCM. Passlock may also be pissed at you.

 

[Schurkey]

Perhaps a moderator will move this thread to the Vortec Performance + Computer Swaps sub-forum.

96+ Vortec Performance + Computer Swaps

If you want to do the 0411 PCM swap or have a 1996+ Vortec motor this is your forum!

www.gmt400.com

 

[yevgenievich]

I would use the wiring from 8.1 and splice it into 97. Or complete wiring harness swap. Splice in 4x4 wires. Or maybe it is l21?

 

[454cid]

I would use the wiring from 8.1 and splice it into 97. Or complete wiring harness swap. Splice in 4x4 wires. Or maybe it is l21?

I don't think the L21 was used in anything but the GMT-530.

 

[yevgenievich]

I don't think the L21 was used in anything but the GMT-530.

I am thinking it is likely 2001+. I know c6 corvette dbw pedal is easily installed in a gmt400, not sure on which pedal 8.1l needs

 

[618 Syndicate]

01/02 3500HD GMT400 were the only years an 8.1 was put in a 400 chassis.