my buddy has Trickflow TW Heads, 1.6 RR, Trickflow stage 1 cam, stock rotating assembly and the usual bolt ons. Made 330 RWHP and 390 TQ. Thats with a custom chip burnt.
yeah my 331 with a stage 3 cam makes 391 at the wheels n/a, but I guess it is possible.......don't really know how, maybe power adder like a small nitrous shot, but who konws. I don't think it is n/a.