So there is a wrecking yard near by and Ive been wanting to get a spare motor so I can have it sent to the machine shop and not have my truck down for a while..
This motor is real clean, sitting outside under a carport like structure and I do not know how to tell if this is a 5.3 or 6.0 or what options were even available for the avalanche..
It has the front accessory brackets installed.
im not sure if this helps but the throtle body mounting poriton of the manifold was pointing upwards a bit and was 4 bolt. dont know if thats how all of the newer manifolds are but thats the only other observation I made.

anyone with info, post up..
thanks,
clint

 

Got a VIN # for it?

 

sure dont.. dont recall seeing a tag on the motor either.. think it was recently removed from the truck..

 

what casting number is on the heads?

 

That should tell you, or you can check the RPO codes in the glove box...I'm sure someone here has them and can post them up for you. Most of the Avy's are 5.3's I believe, unless it's a HD Avalanche. If I'm right about the HD thing, you should be able to tell by counting if it has 6 or 8 lug nuts...but I'm not 100% sure about that.

 

Get the casting number off the block is the only way to tell.

I believe you basically have four options:
L76 (6.0L, cast aluminum, AFM, VVT)
LMG (310hp 5.3L, cast iron, flex fuel, AFM)
LC9 (310hp 5.3L, cast aluminum, flex fuel, AFM)
LY5 (310hp 5.3L, cast iron, AFM)

 

it should say 4.8/5.3 gen iV on the block ...