sounds like an fbody longblock with truck intake.

 

You can find the block casting number
On the backside of the block( behind the
flexplate) if its out of the vehicle...
The serial number is on the rear left side
Of the block , right below the cylinder head.
It looks like the old " Dot matrix" numbers/ letters.
Might have to wire brush the surface to see them
Though. Hth.
Ben Smith

 

Please help is it a 5.7 gen 3 or is it a 6.0 ?

 

Cable throttle body tells me 5.7.

The 6.0's that came in the cars with car intakes are DBW. The 05-06 GTO and the corvettes at the time all used drive by wire throttle bodies. Cable throttle body and car intake points towards a 5.7.

Also the cylinder head casting number and the date printed on the front of the block near the water pump should also tell you what month and year it was made. It's like a 4 digit code I think with 1 letter and 3 numbers.

 

It's a 99 LS1

 

Now sell it because people think they are worth gold, then pick up a 5.3 for 1/3rd the price. Use the rest for mods.

 

Where are you finding block casting number decoders.. I had a guy biuld mine 7223 miles ago an he ripped off my heads an roller rockers an cam, they came stock in my motor bought the truck brand new off the dealership floor.. it had 260k miles an I hydrolock it.. 7223 miles an it blew again.. got back a biuld that my 3 year old could have done.. back to my original question.. it is out of a 06 GMC Sierra 2500 hd I know it's an LQ4 but no idea what the rest of the specks are..