Help Identify LS6 versus LS2 heads
All #243 heads are LS6/LS2 they are the same bare casting with identical ports 210cc/70cc, 64.5cc combustion chamber. They both have D shaped exhaust ports. If you look at the exhaust side of the head, you will see triangles cut through at the spark plug location. This means that the head is a SPM (Semi Permanent Mold) casting. Without these cuts, you will have an inferior flowing sand cast head that is worth a 10hp loss. You can call those LS2 based on their manufacture date sometime in Sept. of 04' and on, but they are totally the same bare head. I reused my sodium filled valves on my Stage II LS6 #243 heads.
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Originally Posted by zo6vetteman2003
All #243 heads are LS6/LS2 they are the same bare casting with identical ports 210cc/70cc, 64.5cc combustion chamber. They both have D shaped exhaust ports. If you look at the exhaust side of the head, you will see triangles cut through at the spark plug location. This means that the head is a SPM (Semi Permanent Mold) casting. Without these cuts, you will have an inferior flowing sand cast head that is worth a 10hp loss. You can call those LS2 based on their manufacture date sometime in Sept. of 04' and on, but they are totally the same bare head. I reused my sodium filled valves on my Stage II LS6 #243 heads.
They are a D shaped port, the flat portion it out of view at the bottom. Here is a pic. of a LS2 head exhaust port.
http://www.gmhightechperformance.com.../photo_08.html
Most headers come through with round inlets at the collectors. On my Kooks, I had to use a GM LS1 2 piece gasket.
http://www.gmhightechperformance.com.../photo_08.html
Most headers come through with round inlets at the collectors. On my Kooks, I had to use a GM LS1 2 piece gasket.
Last edited by zo6vetteman2003; Aug 2, 2006 at 07:51 PM. Reason: spelling error
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Alright, I can see that I was probably missing the actual shape of the port because of the carbon build up around the port making it look circular. Kind of threw me for a loop because when I went to get new header gaskets the guy at the parts counter said "you need the ones off the new vettes" and sure enough they fit perfect. Why use a D-shaped gasket on our cars and a circular one on the 05-up if the head is the same? Thanks for clearing this up for me and sorry if I caused any confusion.
Originally Posted by muncie21
Actually they are round port. Here's a better picture.
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