Let me suggest that you consider another option, since you're getting pretty sophisticated with this sort of modification. Install studs, not head bolts into at least a few places in the block to check for bolt hole clearance. Using studs in all the holes is best. You might have to enlarge the bolt holes to avoid interference problems. This should probably be done on a Bridgeport mill, with the head gasket surface clamped to the mill table, on parallell blocks to allow a drill bit to extend through the head without contacting the table. There should be enough thickness in the casting to enlarge the holes 1/32" or so. Follow up by spot-facing a 1" diameter area at each bolt hole, and use a hardend steel washer between the nut and the head surface. This is pretty much standard procedure on the blower-equipped hemis we run on the tractor pull circuit. For some reason, head gaskets don't blow as often on engines with studs instead of head bolts.
Porting- - - -Usually, "less is more". It's easy to grind through into a water passage and ruin a head after doing lots of expensive work, and the stovebolt head doesn't gain much flow advantage even with radical port modifications due to the cast-in restrictions in the ports. Just clean up any roughness and smooth the passages, and maybe install the oversize exhaust valves that were used on Powerglide cars along with some pocket porting to improve gas flow around the bigger valves. The modifications you're suggesting will only be effective at or near full throttle- - - -big valves and ports have a tendency to reduce, not improve low end and midrange power.
Jerry
