[sfont66]

Originally Posted by MDPotter

The L33 is a good engine! I have lots of advice I could impart on you, but what comes to mind right now is work to that engine before you drop it in. I don't know how many miles are on it, but I would recommend replacing a lot of parts while it's on the stand and easy to work on. I did some of these to my LQ9, but not all of it and am regretting it now:
-Rear main seal - this is what I believe is leaking on my truck now and I don't know how to replace it without pulling the engine.
-Front timing cover gasket & crank seal
-Spark plugs and wires
-Water pump
-Idler and tensioner pulleys
-Power steering pump
-Intake gasket
-Knock sensors and harness (seal the perimeter of the rubber boots with RTV)
-Oil pickup tube o-ring and oil pan gasket. My dad has a 2006 Sierra with the L33 and we replaced this a couple months ago as the oil pressure was pretty low and you could hear the lifters on startup. Not too bad up on a lift, but much easier on an engine stand.

Other things to consider: electric fans, hydroboost (awesome upgrade and not expensive if you go the junkyard route), Vintage Air or keep the factory heat, what route you want to go for the LS wiring harness/computer, any engine upgrades (cam and springs is easy and gets you more power and lopey idle), headers or manifolds (recommend manifolds), what engine mounts to use, what fuel tank/system to use, etc.

I don't want to clog up your thread here, but I'm happy to give you any info on my builds.

Thanks for the reply, and info
The engine has over 100,000 , so I will take your advice and do most of those maintenance items.
No problem clogging up the thread, any info is appreciated.
It’s still early in this project as far as the LS is concerned, and I haven’t done much research, I will review your build threads, as I have many questions
I don’t like wiring very much, but feel I could modify a stock harness, but I really would like to hide as much wiring as possible, and the Ecu. Also how is the original cab wiring integrated into the Ls engine harness. Many questions in the weeks ahead.
This truck is radio and heater delete, so lots of room behind the dashboard to hide Ecu?
I like the idea of Hydro boost and electric fans.
What motor mounts are best and location.
I will most likely install a new cam and springs. And am considering a different intake and larger injectors, and possibly porting and milling the heads.
I have some time to gather parts, and more info as I plan on tackling the frame work first, then engine and transmission, wiring etc... then the box.
Thanks again for any and all info