bad day on the madien voyage

I dont know if anybody has mentioned this or not but a couple years ago my brother put together a 340 that had the same problem and it turned out to be the heads and block had been cut so many times for diffeent rebuilds the heads bolts were too long and bottomed out but acted like they were torqued. The leakage only happened after a few heat cycles. I think he stuck washers under them to test his theory and figured it out that way. Hang in there and the end result will be worth it