317 Castings?

[MikeMoss]

What is the difference between the 243 and 317 castings, the way I understood it was that the ls2 got 243 castings but I found some that say they are 317 castings.

Also will the 317's bold direct ally onto a 2001 ls1 block?

thanks

[jay_lt4]

317's came on 6.0L engines, they are the same port design as the 243's but the combustion chamber is larger for the 6.0L engine,, yes they can be used on a ls1 but your compression will drop

[powermad]

[MikeMoss]

Ok so I got that, but what about 799 castings I have read that they are the same as the 243's.

Also I read about a center bolt design and a perimeter bolt design how do I know which I have and that I buy the right heads?

My car is a 2001 Camaro that currently has 241 casting heads.

Does anyone know if a set of 799 castings made in 2007 would bolt on correctly?