So when I picked up my car yesterday I brought over to a friends house to have him check out the headers and everything, and he pointed out the heads were aluminum and had a HB sticker on the front of the head and "853" engraved in it with a much longer part number underneath it. Ive been looking online but I cant find anything, is this a stock piece?

 

#853 is one of the casting numbers for stock GM LS1 Heads. they have a 66.67 cc combustion chamber, 10.1:1 compression ratio, 200 cc intake runners, 2" intake valves and 1.55" exhaust. Sick

 

Um....the whole engine is aluminum.

 

righteous