this is what i wrote meaning the 99-2000 6.0 engine will have iron heads not aluminum, you saying it should read cast iron heads.ok got it

 

lol no, see post 6

 

Put down the keystones Gonzo Lol.

This sounds like it could be another GM off ball .

I do know that in 99 they had a light duty 3/4 ton , it had 8 lug wheels , and the non buldge hood on it , front end looked identicle to the 1500 .
I assumed it had the 6.0/4L80e , as like said a true 2500hd had the 6.0/80e , I'll bet money it's not a 5.3 /60e in this truck .

 

The 2500HD was not released until 2001

99 and 00 model 2500 trucks were considered a light duty. I don't believe they ever had the 5.3L in the regular 2500 trucks. I have never seen a Factory tune supporting that theory either.

Either way the 8th Digit of the Vin code will tell you what factory engine was installed.

For the model year 2000 GMT 800 trucks across 1500 and 2500 line up with gas engine's

V= VR4 4.8L
T= LM7 5.3L
U= LQ4 6.0L
G= L18 8.1L

X= LF6 4.3L Crappy V6 option

https://service.gm.com/dealerworld/v.../vincard00.pdf

 

 

Great info btw Joeseph !

 

Back when those trucks came out, I did look at the brochures and you could get a 5.3 in a regular cab 2500. I am unsure as to which transmission was offered though...