The carbs were rebuilt stock a few months ago, they're 390cfm Holley 4160 vacuum-secondaries with stock jetting, running sync'd (as opposed to progressive.)

The temp gauge wasn't working but it wasn't overheating or steaming or anything. I stuck a thermometer in the radiator every trip for the first month or so that I was running the car once I put the tunnel ram on; it was running cool. Granted, I got out of this practice. (Hey, what could go wrong, right?)

By the time I got it to work (the 4 miles after it exploded), it was overheating like a mo'fo and the radiator was practically empty.

Yesterday morning when I took out the oil pressure sensor, the block peed antifreeze for about fifteen minutes. There was as much coolant in the block as there was left in the radiator.

Possible the block had cracked, and that made the engine run hot enough to self-destruct?