I have an 07 sierra with a 5.3 and 243 heads. Was wandering the difference in other 243 casting heads if any.

 

I believe they are the same

 

Should be the same. I think only the Z06 243 heads had the sodium filled valves

 

Exactly the same. Like white1 said, the only variance in 243 heads are the LS6 version with hollow intake and sodium filled exhaust valves.

 

same but different springs. the ls2 243 has ls6 yellow springs.

 

Are you sure the trucks dont have the yellow ls6 springs?? Im just asking because I saw a truck engine for sale with the valve covers off and thought I saw yellow springs. Im not sure, just asking. I thought the trucks had the standard springs till I saw that pic

 

Naw the trucks don't have yellow springs