Man, you guys baby those engines of yours. "don't hold her wide open for more than 30 seconds?". "2 minute wide open!!"
You should come river boat racing. I have held my 434ci wide open for 40 minute legs in some races. Then the next day, do it all over again! 500 miles is a marathon race. I've used this engine for 2 races and lots of running around. The leakdown and compression test says that it's in great shape. Your motors should last longer than you.
Oh ya, I run a 8 quart Dan Olsen pan and Steiger cooler and once the temp hits about 240 / 250, it stays there for the full leg.