[Elarson]

Originally Posted by Tom Vaught

Head Bolt IS Different BECAUSE, a Head Bolt is torqued to a given condition by reacting against the head and its support structure.

So now you have cut away the support structure and you want to put a "push rod bronze sleeve" back in to seal up the hole but you think nothing about the loss of clamp load on the head gasket at that point on the head?

I have seen guys narrow the boss between the two runners on a normal cast iron Pontiac head and later they could not hold a head gasket. A cast iron head, not a softer aluminum head. Sorry but I think that you are missing the point here. It is not to seal up the oil leakage, etc, it is to be able to properly clamp down the head and have a head gasket hold under high boost pressures.

Tom Vaught

When I designed our billet RAV heads for the funny car, the very first design parameter was to define a 1/4" wall around all of the head bolts. NOTHING that was put in after that (ports, oil drains, etc) was allowed to violate that space. So far, the head gasket sealing is excellent even with the violence of nitro.

Eric