dyno #s seem low ?

Did the OP happen to read the dyno derby 390hp 340 with a XE268 cam article... :)

Disney has a place for that 390hp engine... fantasyland.

OP's engine should make 330-350 at the crank on a good tune up. 271 at the wheels with this build is pretty good. Should be good for mid 12's at 105-107ish range in a decent 3200# A body