MCMLXIX

I am installing new heads. The new head gaskets Fel Pro 1003 say to drill a 7/16 hole between the center cylinders in the deck of the block. Is this realy necessary? I am a little reluctant to drill the block in the car. There are already 2 smaller holes right next to it. Should I open up the 2 other resticted holes to 7/16 or just drill the block? Any advice to drilling the block in the car.

Thanks

The Dude

This deck mod can be a good idea, especially with the 400 SBCs. You may want to do this before you take the block to be tanked, though. I've never heard of this on 350s.