pwrtrip75

iTrader: (8)

How many different castings are there of these heads and what is the difference?

Thanks.

HSV-GTS-300

Search: Key Word(s): 5364

WKMCD

iTrader: (2)

Short answer is there is no difference if you are looking for CNC'd heads. One is a rougher surface than the other.

8ByGoat

iTrader: (2)

823's are superior if you are not porting-but I think you will be hard pressed to find some.

They are a "smoother" casting and have bigger exhaust ports.

69LT1Bird

iTrader: (1)

The exhaust port is not that big of a difference, a port match to the exhaust gasket would take that difference out of the equation. Also, the smoothness difference of the ports is from the casting process used to manufacture the heads. The truck ones are made in a larger quanity so cost and speed determines that process. A bit of light sanding and polishing and they will look like twins.

Plus if you buy new ones today, the L92 and the LS3 share the same service part number - 12615361