help me identify my ls engine

[henry3rd]

Hey guys, I have been wanting to do this swap for a long time.Traded a mossberg shotgun for a 4.8 engine(I think) It has this number stamped into the block on the back 12567392 and the head gasket tab has a 4.8 on it.
I dont know what year it is.It has drive by wire and the connectors that go into the computer are blue and green.The guy I got it from took it in as trade for something and doesn't have a clue.It has the wiring harness but not the computer. I looked on lt1swap.com and the 2004 wiring diagram is pretty close but the c100 pinouts seem to be wrong and the wires from the big round connector that I assume is for an automatic trans all the wires are
right except for the gray wire which is the low reference goes to pin c1-47
which the 2004 wiring says is not used.I was thinking it was a 2002 to 2004
engine but I dont have the pin outs to tell.when I get a pcm for the harness
what year should I get? there is a big white sticker with a barcode on it on the back of the drivers side head does those numbers mean anything?
Thanks for the help i know I'll have a ton of questions as I go..

[clinebarger]

The Blue/Green PCMs were used from 03 to 07. If it has a fuel pressure regulator on the fuel rail Its a 03. There should be a tag on the harness near the PCM plugs that has a date (Example: my 04 5.3 has 8-24-03 on the harness)

[henry3rd]

bummer, it has no tag on harness. It has two lines going into fuel rail so i guess it has the regulator built in?

[clinebarger]

Originally Posted by henry3rd

bummer, it has no tag on harness. It has two lines going into fuel rail so i guess it has the regulator built in?

Two lines means its a "return style fuel system" Yes the regulator is built in. If the engine is out of a truck its a 2003 model, Vans had there own thing, Not very familiar with the vans, But there easy to spot by the extra long oil dipstick & tube.

[matthew20061]

On the front right side of the block, under where the alternator bracket mounts it should be stamped 4.8/5.3L. Usually there is like a check mark on which one it is, but sometimes its not there. Might give you another place to look.

[structures]

If you knew the transmission that was mounted behind it that would help provide a clue. My engine/tranny were purchased together and the combo was sold to me as a like an 04/05 5.3 4l60e, but I later saw the head gasket tab with the 4.8 stamped into it, then after reading the crank casting number verified it was a 4.8. Later down the line I changed the oil in it. Went to put in the oil filter and the one I bought like 06 and older (ac delco pf46... i think) turned out not to fit. After buying some other filters it turned out the filter that fit mine was for an 07 and up. Then I noticed my transmission case had a character code that started with 7. Which I later found out represented the model year 2007. So as of today I'm assuming I own a 2007 4.8l 4l60e until proven otherwise.

The whole LS swap has been quite the learning experience for me. It's been fun though.