head gasket not round?

I purchased a fel pro head gasket and the shape of each hole is not round nor is it the same from hole to hole. it is not symmetric front to rear of the engine. i even ordered another one in to compare

I am looking to put in larger valves into this auzzie head and would like to scribe the head using the gasket. and then lay back the walls to unshroud for the new larger valves....

has anyone seen this before?? do i unshroud to a perfect round hole?

let me know,
Pete

Pls have a look at this link - mikes ported alum head - can see the circles corresponding to the bores scribed on.

http://fordsix.com/forum/viewtopic.php?t=48721

so my guess is to grind back to the bores diameter- NOT the gasket shape - but i aint no head porter!

the gaskets here in australia ( monotorque brand) also exhibit the NON circular gasket face

brett
Melb

If you look at the gasket mounted on the head, you'll see that the oblonged area is always around the intake valve. This is designed in there to give a bit more valve clearance.
If the gasket was round like the cyl. then there would be gasket material exposed on the head side and it would burn past the fire ring.

I tried to fix this using a copper head gasket with round cyl. holes, but ended up machining out the valve clearances anyway. Mainly due to possible hot spots on the gasket causing pre-ignition.

Will