I know this is a LS series forum but I thought someone on here would know about this stuff.

I have a couple of Vortec heads that I would like to get more info on.



Casting no-12558062

What I think I know.

'98 5.7 L31 64cc 1.94in 1.50exh 170cc intake port

I'm keeping these.



Casting no-12552520

What I think I know.

'97-up 5.0....

These are for sale.



Casting no-10239906

What I think I know.

'96-up 5.7HD L31 64cc 1.94in 1.50exh.......

I've heard that these have a hardened exh seat that somewhat restricts flow but can be reworked to be very nice heads.

These are also for sale.



What I would like to know is port size and valve spring specs, ie.spring rate and max. recommended lift. And any other good useable info.



All these were removed from low mileage engines and in very good useable condition. I will post them up in the for sale section when I have all my stuff ready to go. I'll also have some engines and misc stuff.



Thanks for any info.



Thom.