Did you put those 799 heads on the l33 you have? If you didnt you have a lm4 then, basically a l33 but not as much hp/tq as the l33. the l33's have 243 heads i believe thats the # (same heads off c5 z06's).

 

The L33 could have the 243 or the 799 heads on it. Some even have one of each.

Mine came with 799 heads on it.

 

no they came with the 799s witch are the same as 243s minus the sodium filled valves

 

anyone wanna give me some idea's on how much hp will full exhaust,ls6 cam,cia & tune make?

 

so would that not make it a lm4 then? im trying to figure this out because i have a l33 with the 243 heads. which im for sure is a l33 and from everything ive seen, read, and talked to said the aluminum 5.3 with 799 heads are lm4's which like you said above only have those difference's. maybe someone else can chime in also. i'd like to figure this out not trying to argue.

 

As far as I know, the LM4's only difference from the LM7, is the aluminum block. LM4's were used in V8 Envoys & Trailblazers, and Rainiers, and only for a short time.

If you have an aluminum block 5.3, and it has dished pistons, then it's a LM4. Flat tops would make it the L33.

 

LM4's use dished pistons land 862 or 706 heads like a LM7 but without the cast iron block. HP is no different than a LM7

L33's use a flat top piston with 799 heads, some had 243

LS6 cam is not good for a truck, maybe you can pull it off in a RCSB but not anything heavier.

 

Says who? mine runs good 243 heads and ls6 cam 13.8s in a xcab

a scsb will run mid to low 13s with that setup

 

Says me...after installing a crate LS1 in my Avalanche, then swapping to a LS6 cam several months later.

 

idk what you did but mine runs good