In 2000, TSE Class Legal, my car 3700#, 9.13et @ 153.55mph, Reg GN-1's Ported by Dan Strezo (DLS), PT88 3-bolt, choked with a 3" D.P. & Full Exhaust required by rules.
(Approx. 1040 RWHP)
I think the Reg GN-1's are just fine Ported up to at least 1200-1250 fwhp.