I live in the same town where Tony DiCosta had Hot Rod and Custom Supply. Tony is one of the best flathead builders around, in my opinion. He built the flathead that was in Total Performance's pink T bucket, and he sold the engine for $ 9 K when he got it back.

Anyway, Tony told me one time you have to buy 10 flatheads to get one good one. They are prone to cracks in the valve seat area ( I think) and maybe the water jackets. The only way to tell is have one magnafluxed to see if it is ok before you start spending money at the machine shop. The other problem, is that flatheads are not cheap to build.

I know they are the hot setup right now, but they are not without their pitfalls.And they tend to run hot, too.

Don