Are all 243s pretty much the same head
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
Are all 243s pretty much the same head i wanna know of there is a difference between car and truck 243s. Disregard the casting marks, and im almost positive only ls6 cars got the sodium valves, and im sure trucks got different springs, ignore that too since we all hopefully swapped those out if we are outting 243s on a cammed car, what i just wanna know are the chambers the same size, are the heights all the same size, and are the valve diameters all the same regardless if its a truck motor, ls2 or ls6.
Im pretty sure that i know the answer and that all 243s are the same, besides how they are cast, spring type, and valve material
Im pretty sure that i know the answer and that all 243s are the same, besides how they are cast, spring type, and valve material
TECH Senior Member
Joined: Jun 2016
Posts: 22,301
Likes: 3,625
From: Central Cal.
All 243's and 799's are the same head. The only differences are in whichever valves, springs, etc. used for the application. The 799 is a later casting used heavily in late 5.3's in trucks. Same head, just a sand casting instead of die-cast. They ARE interchangeable.
TECH Regular
Joined: Feb 2017
Posts: 436
Likes: 29
From: Michigan
From what I have herd from my buddy who works at gm all the 243 heads have the sodium valves the only reason the trucks that have these heads have them at all is because they ran out of the regular heads that they did production with and only had the 243s sitting around so them motors got 243 heads instead of stopping production to wait for other heads to come in, cant say if its true or not just going off what I was told, but knowing how the automotive production world goes I can see it
TECH Senior Member
Joined: Jun 2016
Posts: 22,301
Likes: 3,625
From: Central Cal.
Actually, 243 and 799 heads are identical, and the only 243 heads that got sodium valves went into Corvettes and maybe CTS-V's and GTO's. The truck engines got the bare heads dressed out the same as the 799's with normal valves, etc. The only difference between 243 and 799 heads is 243 is die-cast and 799 is sand cast. TOTALLY interchangeable.
