5.3 Swap into my 72 c2500

[72GreenMonster]

This site has given me knowledge to keep my monster driving. Thank You to All for sharing your knowledge and solutions. Previously a 402 soon to be a 5.3 something

New challenges for my swap / hopefully some quick answers.

Acquired what appears to be 2002 Tahoe 5.3 engine assembly semi complete and a bit tattered from the wrecking yard.

I want to swap into my c2500 on the cheap asap. Road map to how from the experts in this forum. Here goes! How would you do it??

Most critical first

1.I have no ecm and original harness is unrecognizable. Don't mind stock look and parts or do I chase down a intake with MSD LS or sniper efi? Kits runs around $1200 without intake. MSD kit with intake runs $700 but still need carb? What do I do? , Stock exaust manifold ? will it fit or do I need headers to not cut and modify. I want to minimize fabbing. I know$...

2. What I have Truck intake, not sure if it is dbw or dbc, how can I verify?
No alternator, has steering pump so for my truck do i move accessories around to avoid notching the frame or what setup goes in easy without notching the frame? Tahoe Oil pan Okay? not lowered? towing... which engine mounts for our trucks? Previous BBC mounts remain. I plan on bolting up to my TH400 for now to get up and running. flex plate adapter I know about.

These are the immediate hurdles that come to mind which will tell me which direction I can take. With what I've seen it can cost as much to get a harness and pcm $950 to go stock and get things going. or LS carb setup (I know?).
Don't mind getting everyone's advice.

There it is!! What do I do ? Please tell me so I can get started. I was so amped I nearly stripped down the whole motor in a few hours.. Pics to follow.

Thank You
72GM

[mongocanfly]

Dbw and dbc

[mongocanfly]

Looks like you've got your work cut out for you...
The stock LS accessory drive will work..no need to relocate those..
I'm not sure on the bb mounts...on mine I used Ebay adapters and stock sb mounts...
You should have gotten a ecm with the engine...what throttle you have will dictate what ecm you need...all this stuff needs to match..if dbw the youd need the gas pedal setup to match it...
if your on a budget you can rework a stock harness..
Theres also the Ebay harness like rabid dentite is using in his post below...
http://67-72chevytrucks.com/vboard/s...d.php?t=780507
Skip the msd/sniper setup...and I'd say no to a carb....stock LS setup is fine...
I think ls3 or tbss manis will work...
Sanderson makes LS headers for the 67-72 trucks...
I used stock truck oil pan with no issues
Dont forget you'll need ecm flashed and the fuel system as well....
If you got a mystery motor I'd tear it down for a inspection...

[72GreenMonster]

Originally Posted by mongocanfly

Looks like you've got your work cut out for you...
The stock LS accessory drive will work..no need to relocate those..
I'm not sure on the bb mounts...on mine I used Ebay adapters and stock sb mounts...
You should have gotten a ecm with the engine...what throttle you have will dictate what ecm you need...all this stuff needs to match..if dbw the youd need the gas pedal setup to match it...
if your on a budget you can rework a stock harness..
Theres also the Ebay harness like rabid dentite is using in his post below...
http://67-72chevytrucks.com/vboard/s...d.php?t=780507
Skip the msd/sniper setup...and I'd say no to a carb....stock LS setup is fine...
I think ls3 or tbss manis will work...
Sanderson makes LS headers for the 67-72 trucks...
I used stock truck oil pan with no issues
Dont forget you'll need ecm flashed and the fuel system as well....
If you got a mystery motor I'd tear it down for a inspection...

Mongo,

Thanks for the feedback! Here is an update:
Taking your advice and staying close to stock. Do have some work to do.
So couldn't get the ecm and harness with the assembly but for $450 i will find the ecm. Did buy 02 pedal and TAC on ebay for $75
Looking for a trailblazer exhaust to avoid notches.
Have a leaky oil pan from the wrecking yard forklift. (Can it be welded?)
Mystery motor for sure: Looks like a high miler but untouched. Please have a look and let me know what you think:

Have done some part shopping: The plan:
Summit Truck Cam Stage 1 high lift
LS6 Springs, Seals, New stock lifters
Timing set, Oil Pump, Gaskets.

Fired up but I am learning to slow down and walk down. Excited about the build.
Thanks Again
Trying to upload the pic but i get a security token message?

[mongocanfly]

oil pan can be welded if needed, but are cheap enough id just grab one from the junkyard...
if your going to change lifters you have to pull the heads to do so..this will require new head bolts...head bolts are tty one time use only
don't forget...ecm,harness,pedal,and throttle all must match

[72GreenMonster]

Originally Posted by mongocanfly

oil pan can be welded if needed, but are cheap enough id just grab one from the junkyard...
if your going to change lifters you have to pull the heads to do so..this will require new head bolts...head bolts are tty one time use only
don't forget...ecm,harness,pedal,and throttle all must match

Pulled the heads
Going to get a valve job and new springs and seals put on.
Did buy new felpro torque to yield bold kit.
Homework tells me I need a 411 pcm. Will share once i locate. and match.

Thank You

[72GreenMonster]

Here is a pic of the block

[72GreenMonster]

Cam

[72GreenMonster]

Heads

[72GreenMonster]

chain

[mongocanfly]

just so you wont be shocked...a new LS timing chain will be/look loose...about like your pic...and the oil pump will need shimmed
you said you bought a pedal and tac...so I assume you have dbw throttle?

[72GreenMonster]

Originally Posted by mongocanfly

just so you wont be shocked...a new LS timing chain will be/look loose...about like your pic...and the oil pump will need shimmed
you said you bought a pedal and tac...so I assume you have dbw throttle?

Dbw throttle body, while it's accessable, I figured replace what I can being the assembly showed some age. I
I got a melling OP. Can you tell me about the shimming, haven't read or heard anything.
Learned how to prime it tho
Thanks Mongo!

[mongocanfly]

https://www.youtube.com/watch?v=TsC2EtNOOPE

https://www.youtube.com/watch?v=DzUy1RdOx50