I thought I'd start a new thread on this, for those that don't get Y BLOCK MAGAZINE. This is an early 239 looking at cylinder #4. The water passage is at about 2 o'clock. The black magic marker circle is where the water passage is located in newer blocks. To use a newer head on an early block, you need to drill a hole in the block so it lines up with the newer heads. This must be done at #4 and #8.



Be careful when drilling so as not to break off a drill bit in the block.



There's very little coverage with the head gasket at this new water passage location. The newer blocks have a triangular casting at that point. I took the block to a welder and had him weld some triangular gussets for me staying below the deck surface.



I then filled in the area with epoxy and sanded flush with the deck surface.



My 239 is bored +.125 and has a 312 crank in it. I put G heads on it so it flows a little better. Hopefully I'll have time to change the intake from my 354 to a 573 this winter.

  Dennis in Lititz PA