What I am wondering about is if I would gain any cooling advantage from drilling additional deck coolant holes.

My block is a '73 #3999289, I have Brodix BB2 heads. Although the 1027 gasket instructions say nothing about the lower coolant holes, both the heads and the gasket have the 3 larger lower coolant holes, but the block only has the one large lower coolant hole between the two rear cylinders on the drivers side and the two front cylinders on the passenger side.

Would adding 2 additional 1/2" holes per side offer any cooling benefits?

Thomas

I usually drill them.
The instructions that come with the 1037's call for the first two holes to be 1/2 & the third 5/8 but it does not have both of the large holes at the back of the gasket open, only one of them.
I believe the Brodix heads only has one hole open but can't remember for sure??
I am referring to the holes behind the last cylinder, one square & a smaller one that is sorta triangular.