I'm very happy for you, and your 400hp friend, but I'd rather be your parts man. Don't get me wrong, I love Fords, but the 302 is actually a lousy design. There aren't enough head bolts, which is why they blow more head gaskets than any other engine, and the oil pump is in the front. Half of the 302's I've torn down have had cracked piston skirts, too.
I would consider myself very lucky if I were you, rather than start to believe that the endurance you've seen is common.
Take care,
~Chris