KJL

I was reading the installation instructions on a pair of Fel-Pro head gaskets. I says their gaskets have a 7/16" hole to allow more coolent flow between the center pistons, where failure is most likely because the exhaust ports are adjacent to each other . They say all heads have these holes but some blocks don't. Mine don't. I am installing a high volume water pump. wondering if I should try to drill these holes. The block is in the car. Just swapping heads. Any thoughts? :confused:

redwingvette

I drilled mine while the block was in the car. I taped over the cylinders so chips could not fall into them. I had to make a short drill to be able to drill the drivers side because the powerr brake stuff gets in the way of drilling the hole. Place the gasket in position and scribe the hole. Remove the gasket and center punch the hole. Drill a small hole and keep increasing the size until you get to the 7/16".
If you don't want to drill the hole than make sure you open up the holes in the gasket to match the factory gaskets where needed.

KJL

Thanks for the reply, I drilled them out. I unbolted the master cylinder and it moved enough for me to get the drill into place.