[chiphead]

Another excellent example of why to pitch the stock rods on the trash. The pontiac rods do suck that much. For every engine that runs 12s with stock rods, there are 10 that do what yours did. The stock rods can and will let go suddenly, for no good reason. I've seen stock rods go out-of-round, and let go, at low engine RPMs. Of course you should have had the rods re-sized and reconditioned. Did you? The machinist should have at least checked the health of all 8 rods on build. Did he?

You may never know what the failure was. All you're gonna find is a bunch of chewed up metal in there. Unless you find clear signs of loose rod nuts, the oil pump fell off, too tight bearing clearances, or other obvious issues, its gonna be a finger-pointing contest.

If you're lucky, you can save the block. If it indeed threw a rod, I'm sure all the internals are smashed. One good note, I had a friend who's 400 did about the same thing. The internals were smashed, but the block could be saved. Just had a thumb-size chunk out of the bottom of the cylinder wall, which wasn't a problem.

good luck

chip