87 GMC crew cab 5.3 4l80e swap

I finally got some money together to start working on the dually! I wanted to do a cummins engine but i cant find what i want for the right price. After weighing out the cost, amount of fab and mpg. the 5.3 is definitely the way to go. I should be able to have all this done and running for what it would cost just to buy a p-pump 12v. MPG should be similar but gas is cheeper. It will basically drop right in with some adaptors too. I towed my 21ft boat 3hrs up state with the stock 454/th400. Only got 7mpg, took 3 tanks of fuel, and the gearing kept me from going very fast. That BB is gone! 5.3/4l80e going in.

Truck when i first got it

6/8 drop (not complete) and most of the bull s$%^ gone


gas guzzler 454


interior

Last week end i started working on the truck. Got the engine and trans pulled. Pressure washed the engine bay and sold the 454. I picked up a 5.3 complete with everything a couple weeks ago. Hopefully be picking up the 4l80e tomorrow. I started redoing the harness after work this week but its not done yet. I have done a ton of research on this conversion. So if theres some interest i will post all the links, diagrams, parts list, and prices if you guys want. I dont really like typing so heres some more pics!

labeled most of the wires because some will need to be tied into the 5.3 harness


Had a little issue here hoist was low on fluid and wouldn't go high enough.


Thought i waited until winter was just about done but it started snowing!


out and clean


5.3


just got done. really snowing now. We got 6in!!!


Where im at now

killer project man..ill be watchin this

Didn't feel too good saturday so i didn't get as much as i wanted to get done this weekend. I went to the junk yard and picked up a 90 burb instrument cluster. 90 and 91 burbs had a 4l80 in them so they had the electronic speedo cluster. i just have to repin my connector and run the signal wire from the 5.3 pcm to it.

found this on coloradok5.com


went through a tbi diagram to figure out what i needed to retain


the only wires you save out of that is anything that goes to the instrument cluster. most will go to new pcm. oil and temp already go to the cluster.



I tore apart the tbi harness today. most of the positives tie into each other somewhere in the harness. same goes for grounds. this will be the feeds to new injectors. from ecm1 fuse


putting autometer metric adaptor and sending unit in. it hook up to the factory wire and gauge.


there was two oil pressure switches. one controled the fuel pump and one does the guage. the one with the single gray wire does the guage. i put that one in the 5.3. wish it was warmer out so i could paint the block and i dont have enough time to wait for it.


drilled and tapped it into here just above oil filter. its a block off plate for a oil cooler i think. not my idea saw it online some where.



carshopinc.com mounts

Nice progress!

DZL1.

Thanks big bear and DLZ1. When im done wiring i will try to make a new diagram with the 2 harnesses, and a parts list with part #s

looks great. i want to swap a new motor in but makes me a lil :S with the wiring. i'm sure i could pull it off.

Hardest part of the wiring is sorting out all the stuff you dont need. The 5.3 harness could be set up as a "3 wire" hook up and it would run. but you would have no gauges, speedo, all the hots on 1 fuse, etc. Nobody wants that! I plan on making a list of what wires go where and where to find them to make it easier for anyone that wants to do it.

check out these how to videos. I dont like they way they did it but it gives you a idea how to build a harness.
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Tons of info on this site. anyone could print this pin out cut sheet and build a harness.
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maby i'll wait and see what you come up with