81 Square Body, Short Wide 5.3 Swap

[Reuben]

Hi everyone,
First post here and I hope that it becomes a productive one. About myself, my name is Reuben; I have an 81 C-10 2WD Short Wide sitting at the house. Currently, I am deployed to Afghanistan but since I have been here I have been able to at least get the 5.3/4L60E combo for my swap (thanks to my wife). It came out of a 2007 GMC Sierra Classic with 5,000 miles on it. The DBW pedal, TAC Module, Wiring Harness, Fuse Box, and every accessory came with it. Now granted, I can't work on this thing for another three months at the earliest, but I think an all-inclusive thread would go a long way into helping out other square body guys. I understand a lot of people come on here just to ask questions to get their ride finished and then bounce. I think this abuse of the "system" so to speak is wrong and I for one don't like it. SO, I want to change it. What I am trying to accomplish here is one build in the first post, with comments added on. I have to get a little more "Forum savvy" but I want to do it.

Square Body guys, please help me with this, as we owe it to other guys looking to make this swap*LOL*. Okay, we don't owe it to them, but wouldn't it have been nice for us? I've looked through the current builds on here and a lot of them are very, very detailed. I'd kind of like to pull them all together and make an ultimate "Square Body LSX Swap Post". This will be my first swap and I will put some things I am sure or almost sure of first. PLEASE DO NOT HESITATE TO CORRECT ME!!! I want this right for our community. I will begin to post my equipment and plans. As I get additional comments I will edit.

Drive Train

• Engine- LM7 5.3 liter- Stock
Motor mount adapter plates needed. I plan on buying mine
from CarShop, Inc.

• Transmission- 4L60E- Stock
Transmission Crossmember needs to be made in my case. I
prefer the tubular ones common in extreme drops.

• Drive shaft- Not really sure what needs to be done here


Accessories

• Exhaust- Plan on buying S&P headers just because I don't want to
notch frame or grind headers. I'm not sure if anyone else
makes a set that actually works??? Afterwards, I will use the
exhaust that is already on the truck. Last year, I put new
cats, Flowmasters, and side exit (behind rear wheel)square
Z28 tips on the truck.

• Fuel System
Sending Unit- I'll be installing a late model K5 Blazer tank and will be using the stock(K5)
sending unit.
Fuel Lines- Where do I get stainless lines made and what size will
I need? Where do they connect?
Fuel Pump- Walbro255
Fuel Regulator- Pretty sure I need this, but what kind is best?
Fuel Filter- I assume Corvette as well

• Air Conditioning- I have a functioning set up in my 81 already. I
assume all I need to do is to flush the system, put a
dryer, orifice tube, and new compressor fittings
(adapters) on my lines. I realize I need a bracket so I
don't have to slice my frame. Are S&P the only ones
who make this as well?

• Cooling system- I realize I need an upper and lower radiator hose
adapted...any suggestions? And what else do I need
to have done. I realize I have to route or plug some
steam lines? How did you guys do yours?

• Power Steering- I believe before it is said and done I will be putting a newer steering box on the truck but for the conversions sake, what adapters do I need to go from the 07 Pump to the 81 Box?

Electrical

• Wiring Harness- Probably will wire my own.

• PCM- I think I will give LSXTune.com a shot.


Well, that’s it for now, I will check back later for suggestion and revisions. I hope this helps.

Reuben