Replaceing a GenIII vortec with a GenIV in an 2000 silverado.
 

I've got a 2000 silverado with 190k on a tired old 5.3l.
I've got an extra 5.3l from an 2009 silverado that rolled with 12k on it.
Can i swap these 2 with out buying a whole new wiring harness and ECM?

First off welcome to the forum. Your in the wrong section to ask this question.
You can swap both motors but you will need a reluctor wheel converter box like this one, and you have to extend your knock sensor, and cam sensor wires since they are a bit different.
http://i94.photobucket.com/albums/l8...00327-1305.jpg
http://i94.photobucket.com/albums/l8...00327-1304.jpg

Opps, sorry for posting in the wrong section I wasn't sure where to post.

Thank you for being so helpfull. Will this do away with all the VVT stuff?
My electical guy was trying to run up huge bill on me to do the swap. this just saved my butt.
Do you know if they make an adapter to swap in a newer 4l60e?

why swap to a newer 60e? its the same transmission.
also you dont have to move the cam sensor harness, its going to plug into that reluctor wheel conversion module. then its going to go to the new cam sensor on the front cover. also like mentioned you have to move your knock sensors to the side of the block where the Gen IV knock sensors are. drill the hole NOT TO DEEP with a 11/32nd and tap it with a 10mmx1.5 tap. thread in your old knock sensors. dont buy a new harness, and reuse your current ECM, all you'll need is a DBC TB (4 bolt 90mm) your sensors from your old TB will fit the new one. you will need the 8 new pigtails for the Gen IV injectors to swap into your current harness, or you could just swap injectors your choice. id keep the Gen IV injectors to save time/money on the swap unless you're already going bigger injectors.

i did the same thing in my 94 chevy there is a write up in the project section. feel free to PM if you have any questions. i had to find all that information out on my own bc i couldnt find anyone else that's done the Gen IV swap into an older truck.

he can reuse his stock 2000 5.3 intake.

true but being on the "performance" side of it id rather the 90mm intake. his choice. also the 09 5.3/6spd is different, i dunno why i thought he was looking at an 08. if ypu want the 6speed an money isnt an issue buy the whole combo. but i recommend sticking with your current tranny or buy a low mileage 60e while your at it

or get the 60e built an i mean built good

True but a "Built 60e" ranges from 1900-2800 so its konda gotta go by his cash flow and use of the truck.

I've already got the genIV and 4l60e that was mated to it. so thats why i was wondering about swaping in the new tranny. Its got an extra speed sensor or somthing along thos line and i wasnt sure if it will work.

if it is a 2009 5.3 it is not a 60e it is a 6L80E and it's a lot more indepth than just "installing" the tranny is controled by its own TCM vs how your tranny is controled now.

i hope you have the harness/ECM/TCM and a few other things that im sure im missing.