Mine never overheats either, although thanks to the TH400 it does run a little warm after extended idling in gear at the Dream Cruise, but if you try to run 93 there is an audible difference in the sound of the engine and power underfoot. Plus, of course, the detonation.
No, my block has never been machined. All the parts are original, all the way down to the head gaskets, with the exception of the timing chain. Simply changing fuel makes all the difference with this as-built engine.
As soon as any modification--whether it be head gaskets, pistons, decking the block, or heads--are introduced, the entire formula changes. That's why the machinist is the key to the build. Everything has to be done right, and documented. And, more importantly, there has to be a plan, and it should be provided by someone with extensive Pontiac experience.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
