LS heads and casting #'s

**jfrc2000** · 03-17-2008, 11:16 AM

Do all factory based LS heads have casting numbers on the corner of the head? If there are no numbers, then it's aftermarket?
the ones i know of......

241- LS1, 97-04
243- LS6, 01-04

plus there are the LS2, LS7, 5.3, etc.....

**kev70ss** · 03-17-2008, 02:37 PM

all factory heads should have castings.
97-98=806
99-00=853
01-04=241
ls6=243
ls2=243
5.3=862

**ccusum** · 03-18-2008, 05:42 AM

I have 243 on mine what does that mean? What is the difference?

**shady milkman** · 03-18-2008, 05:45 AM

you are one of the rare few f-bods that got some ls6 heads..well actually probbally just after market

**ccusum** · 03-18-2008, 05:51 AM

Originally Posted by shady milkman

you are one of the rare few f-bods that got some ls6 heads..well actually probbally just after market

I doubt it is aftermarket. She is a 2 owner car, and I am the second owner and the old geezer that owned it before me I don't think he did a head swap.

**shady milkman** · 03-18-2008, 05:55 AM

well then you have ls6 heads...congrats

**ccusum** · 03-18-2008, 06:07 AM

Okay, I have LS6 heads. What does that mean? Sorry to sound stupid and all. Just trying to learn.

**shady milkman** · 03-18-2008, 07:25 AM

they just flow better..so you are probbally running higher numbers then norm..well shit..you have the ls6 intake, the heads..all you need is the block/cam and tune and you'd have a ls6

lol

**Nitrous** · 03-18-2008, 07:51 AM

If they are aftermarket heads they are usually stamped with smaller numbers. I've never seen 243 heads on a stock F-body but what the hell, they put the LS6 block and LS6 intake in them. I have one in my truck but it came with the 241 heads which I swapped for the 243's when I installed it. The 243's have "D" shaped exhaust ports, higher compression ratio and do flow better. The chambers are 64.4cc where as the 241 heads are 66.7cc. The car would more than likely have to be tuned for the flow increase because my truck ran lean when I swapped the heads out and I retuned it.

**0rion** · 03-18-2008, 11:29 AM

Originally Posted by Nitrous

If they are aftermarket heads they are usually stamped with smaller numbers. I've never seen 243 heads on a stock F-body but what the hell, they put the LS6 block and LS6 intake in them. I have one in my truck but it came with the 241 heads which I swapped for the 243's when I installed it. The 243's have "D" shaped exhaust ports, higher compression ratio and do flow better. The chambers are 64.4cc where as the 241 heads are 66.7cc. The car would more than likely have to be tuned for the flow increase because my truck ran lean when I swapped the heads out and I retuned it.

speaking of your truck.....where's that cotm pic you keep promising me??

**Nitrous** · 03-18-2008, 01:34 PM

LOL I'll see what I can do this weekend since I'm getting a couple of days off. It's not a looker because I need a new paint job and it's a daily driver but we'll see....................