What are the differences in head casting numbers?
I was just wondering if there is a flow difference between the different Gm LS1 castings, because my friend has 241 heads on his 02 SS and that thing flys!!!
241 are found in 01, 02 and in some late model 2000 cars. I have them on my 2000 and they tend to make more power. Some engine builder have claimed 10 hp.

