motor swap help

[quadracerjt]

i just bought a vortec 5.3 out of an 03 avalanche with intentions of transplanting it into my 85 jeep cj-7. my question is, are there any online wiring diagrams of the 03 avalance so i can have reference to where all these wires go and what they do?

[astroracer]

What did you pay for the 5.3? Did you get the computer, exhaust, transmission, rear gears, fuel tank and fuel pump? The reason I ask about price is because, if you paid more then a grand for it, you would have been farther ahead to have bought a crate motor to swap into your jeep. All of the above pieces play a very large role in making that 5.3 run correctly and if you can't get everything to dance in-step your Jeep will never be right.
Mark

[curtis73]

I wouldn't worry too much about getting it to work right. If he has the computer and the wiring harness (either stock or aftermarket) he should be fine.

If you have that kind of stuff I might be able to come up with the diagrams online.

[quadracerjt]

i got the motor w/ ac compressor,alternator,power steering pump, start, wiring harness and computer for $1600. the motor only has 10,200miles on it. the exhaust won't be an issue because my buddy owns a muffler shop, my stock t-176 trans should be able to withstand the 5.3 until i can replenish my funds for a 4L60 trans. i just need to get this thing running within the next 3 months (offroading trip)

[curtis73]

Let me see what I can do about a wiring diagram and I'll PM you later. How are you going to get the t-176 to match up to the 5.3? As far as I know nobody makes adapters, and I think the t176 is a cast-in bellhousing.

You should be looking for a 98-later 4L65E for that 5.3

Just a polite caution; unless you don't have a job and can stay at home all day to do this, figure on more like a year to get that thing in there. Custom welding, driveline angle issues, front driveshaft issues with starters, oil pans, and exhaust, all sorts of things are going to bite you in the butt with this one. Certainly do-able, but this is intense cut and weld kinda stuff, not bolt in by 3 months kinda stuff. The other big issue you'll hit is that if the oil pan doesn't clear the crossmember, you're cutting crossmembers, not oil pans since that 5.3 has a cast aluminum pan that is an integral part of the stiffness of the skirting. You might want to run this trip with the original setup and do the swap later.

Edit: Oh, and you'll need to have someone reflash the computer for the manual tranny. The 5.3 will get all kinds of confused trying to retard timing and fuel curves when it thinks its supposed to shift an automatic. Try www.pcmforless.com

Ah jeez, I forgot something else: You'll have to get an accelerator pedal assembly from the truck as well. That 5.3 is throttle by wire. No cables.

[quadracerjt]

advance adaptors tell me that the t176 WILL work with the 5.3. they make a bellhousing for it. i personally don't see how it would ever take a year to do this. it is pretty straight forward. me and my dad have swapped plenty of motors in different brand cars, none of them with this much wiring tho. it's all about planning. i'm aware of the pedal situation as well...trust me i've done my homework. theres no reason i shouldn't be able to get this done in 3months or less. i've already got the old 258 out and the engine comparntment is all cleaned out and degreased, just waiting for me to get started. i believe advance also sells a crossmember for chevy conversion, if i'll even need it. but if u could give me a little direction w/ wiring that'd be great..thanks