Car made 284whp on a 3.4 pulley, canned tune from me, factory 3" 04+ MAF, modest headers, 2.5" exhaust, and a dyno operator that lifted at 5500rpm before the cam would make peak horsepower...(didn't see anyone else catch that).

MAF upgrade, pulley down to 3.2", retune to bring AFR from the mid 10s back into the low 11s, and get the dyno guy to keep his foot down to 6000rpm, it'll make 300whp with ease.

Lets stop suggesting the heads should be pulled, just for a moment, can we?