5.3L motor swap

[Jfarns03]

Hey guys im new to the forums and im in need of some help. Pretty soon ill start a build thread for my 1968 LWB C10 pickup but right now it will have to wait. My question is how am i going to be setting up all the wiring from the 2004 5.3L motor i just purchased with the old school electronics. Electrical just isnt my thing and im in need of assistance. thanks guys! if someone has a thread made up of a solution please give me the link! If not just hang with me, this isnt my biggest problem yet and believe me i have many more questions about this swap !

[bbadfred]

Check the LSX sub forum it has lots of info. I went the easy way out although more expensive. I used a Speartech stand alone harness and reprogrammed pcm, its plug and play. With the origional truck wiring ( was in geat shape). John Spear is a great guy and is always the one who answers the phone or if you have to leave a message he will call right back. I have an 04 LQ9 6L with drive by wire. Hes really busy so if give yourself plenty of lead time!

[Robznob11]

Originally Posted by Jfarns03

Hey guys im new to the forums and im in need of some help. Pretty soon ill start a build thread for my 1968 LWB C10 pickup but right now it will have to wait. My question is how am i going to be setting up all the wiring from the 2004 5.3L motor i just purchased with the old school electronics. Electrical just isnt my thing and im in need of assistance. thanks guys! if someone has a thread made up of a solution please give me the link! If not just hang with me, this isnt my biggest problem yet and believe me i have many more questions about this swap !

I done my own harness as per lt1swap.com plenty of info on lsx sub forum
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[shearjs]

I, too, used lt1swap.com to do my research and modify my own harness. Just spend some time reading things and doing your research and you'll be fine. You'll find plenty of help here too.

[Jfarns03]

Thanks guys! Yeah I got the complete wire harness and computer with the motor so I don't want to throw away what I paid extra for. I'm glad I can modify the harness to work though! Ill Definitly checkout the other forum you guys referred me too. Was it difficult to get the harness to work?
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[shearjs]

Originally Posted by Jfarns03

Thanks guys! Yeah I got the complete wire harness and computer with the motor so I don't want to throw away what I paid extra for. I'm glad I can modify the harness to work though! Ill Definitly checkout the other forum you guys referred me too. Was it difficult to get the harness to work?
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I wouldn't say it was overly difficult, it just takes some time and patience. Mine was spread out over several wks just here and there as I had time. Otherwise it could have been done in a week just messing with it on evenings I would think.

[Robznob11]

Originally Posted by Jfarns03

Thanks guys! Yeah I got the complete wire harness and computer with the motor so I don't want to throw away what I paid extra for. I'm glad I can modify the harness to work though! Ill Definitly checkout the other forum you guys referred me too. Was it difficult to get the harness to work?
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Start at the computer pins, only cut open about 10" at a time and check and double check (label) all connections and its a breeze! Takes about 5_6 hours at a mild pace
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[Jfarns03]

How do I find which wire is what? I should find a Diagram right?
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[shearjs]

Take a look here , and here . Maybe this will get you started in the right direction.

[Street Smart]

Welcome to the forum! Manhattan Beach? Brooklyn?
We do LS swaps at my shop all the time. I have a buddy with a `49 Buick we did a LS7 in it, he lives near you in Sheepshead bay. I`m doing 2 for customers right now, (57 Caddy and a 70 Cutlass). Let me know if your in Brooklyn N.Y., we can help, I`m on Utica ave.

[Jfarns03]

Thank you both! No I'm actually from Manhattan Beach California. Thanks for the offer though! I will definitely look at those links! I'm not an electrical person when it comes to this stuff
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[Street Smart]

I got all excited, , thought you were from around here. Good luck on your project, keep the pics comimg! We love pics!

[Jfarns03]

heres few pics of the motor i just bought! The first three are photos of removing it out of my other truck and with my coworkers messing around. The last two are photos with the wire harness off. And yes it is hanging by seat belts

[Jfarns03]

Do I need to move the transmission crossmember? Or do I need to buy I new one?
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[88Ironduke]

I've been trolling this website for some time and can offer a couple of generic pointers on the 5.3 install. My current project is a 81' Firebird with a 2006 5.3 install with the 4L60E + drive by wire. The wire harness has been easy, sent the PCM to be reflashed and removed the pins per the links attached in previous post. Of note on the 5.3 were metric threads on the critical ports for old school gages. I had to purchase adapters to screw the standard threaded goodies in to the block. If the donor truck had hydro boost steering you will find that there is no readily available vacume port for vacume assist brakes. A little creative cutting on the EVAP solenoid body, screw in a #6 AN bulk head connector and JB weld to ensure its all locked vacume tight. Depending on the exact model truck your motor is out of Trailblazer SS heater lines and fittings are a sweet install and the QD fittings snap right onto the factory water pump connectors. Once i see how i like the 5.3 it may be a new project for my 72' C-10 LWB truck.
Good luck.

[JointTech]

im pretty sure what your buddy is doing to that motor is illegal in a few states. (not california )

[Robznob11]

Originally Posted by 88Ironduke

I've been trolling this website for some time and can offer a couple of generic pointers on the 5.3 install. My current project is a 81' Firebird with a 2006 5.3 install with the 4L60E + drive by wire. The wire harness has been easy, sent the PCM to be reflashed and removed the pins per the links attached in previous post. Of note on the 5.3 were metric threads on the critical ports for old school gages. I had to purchase adapters to screw the standard threaded goodies in to the block. If the donor truck had hydro boost steering you will find that there is no readily available vacume port for vacume assist brakes. A little creative cutting on the EVAP solenoid body, screw in a #6 AN bulk head connector and JB weld to ensure its all locked vacume tight. Depending on the exact model truck your motor is out of Trailblazer SS heater lines and fittings are a sweet install and the QD fittings snap right onto the factory water pump connectors. Once i see how i like the 5.3 it may be a new project for my 72' C-10 LWB truck.
Good luck.

Actually ther is a round port at the back of the intake (top) it has a plug clipped in it from the factory but gm offers a hose barb that clips into the port. Mine is sill in the package. It was 7 bucks from scoggin dicky. When i get home i could get pt # if any one is interested
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[Jfarns03]

Thanks for the info!

On another note which motor mounts would you prefer? Whats the difference between the two? I know the tubular mounts have a higher clearance but would I be fine to use the LS1 kit with the stock headers? Should i also buy the new transmission mount or can i reuse the old one at the stock location with new rubber?
Part # for the LS1 Engine Mount Conversion Kit by CCP 4810-LS
Part # for the Totally Tubular Small Block Motor Mount Perches 6372MP-T

[88Ironduke]

As long as drive shaft alighment is taken into consideration and is correct they all should work. The only issue I have witht he 5.3's is the placement of the alternator bracket. You either have plent of clearance or not enough to the hood. If I didn't have a cowl hood already I would be tracking one down!

[Jfarns03]

Do I need a new transmission crossmember?
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[joesgreen67]

Originally Posted by Jfarns03

Do I need a new transmission crossmember?
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No....you may need to drill new holes (maybe) but the stock crossmember can be used.