Drilling 750 exhaust manifold gasget?

[XFT LOU]

My sxi pro has brand new sxr bore wisco pistons so I figure it will run hotter. I just tapped the wet pipe manifold for a second cooling line and looking at pic. does anyone enlarge or add more water passages in the gasget? I will have 2 water exits from the head. Thanks.

 

[sflsurfrider]

i think i would. theres not much flow happeneing w/ that gasket like it is.

 

[SUPERTUNE]

I always doubled the cooling holes in the gasket when I built 750 race motors with dual cooling lines. Keep in mind that you NEED to increase the piston to wall clearances if you do!

 

[XFT LOU]

Thanks, I found running the drill bit backwards doesn't "rip" the metal fibers.