FE's are fun.
Seems like I've had more issues with aluminum blocks and Aviaid pans though. I rarely have any issues with the cast iron block combos. Seems like the combos in question are always dry on the dyno as well, but end up seeping weeks/months later. Is it material expansion rates? Possibly. Is it double stacked gaskets? Possibly. Fun stuff, especially when you can't point a finger at anything in particular.