1963 chevy c40 grain truck 6cylinder problems

[gpcoupes]

Hi all and thanks to who ever created this cool site, I have several old chevy pickups, but this time Iam working on my 63 c40 grain truck. i bought this truck to tranform into a car hauler. The problem Iam having is I was experienceing a low whoosing noise when you turn over the engine. it sound like I left a spark plug out that loud, well with the help of my boss (wife) I found a spot where the head meets the block a big whole where the air was coming out? ran compression check and 1 and 2 were pretty low conpaired to the other 4. Iam in the process of going down there this am and removing the head. Its a 292 inline 6. Iam not sure if a head gasket moved or what? Does this engine marry up with any of the other chevy 6 cylinders as far as heads and your intakes and exchaust manifolds?? Any help would be greatly apprated. thanks BW