Allright. I blew my engine up. Old engine + first build + lead foot = my bad. Destroyed the #4 valve and the piston beneath. But when I got the heads off, I saw that the #1 and #5 valves were pink-orange.

This is on a dual-quad tunnel ram. It seemed to be running fine (until it exploded) but it looks like these 2 valves were running REALLY hot. These would be the vacuum secondaries on the forward carb.

I drove it for about 4 miles after the #4 valve blew out (pictured); might this discoloration be a result of the coolant / oil / etc. being sucked into the trashed valve for 4 miles at operating temp, or are my carbs not tuned as well as I thought they were? Plugs were uniform reddish - grayish (except #4, which was bentish - shatteredish.)