Originally Posted by mineralgreyGT
from what I have been reading you can save your money and buy the stock ported heads from these guys Engines & Components : Zen Cart!, The Art of E-commerce
or foxlake and the results are very similar. I am not 100% sure on this but there isnt much information out there regarding the twisted wedge heads either on the 4.6s
That's completely false. There's a lot of info out there on the TFS heads for the 4.6, and they have proven to provide great power increases over anyone's ported heads, Fox Lake or Cushman included.
The Trick Flow heads combined with the proper intake, stock 98 NPI intake will not work, but the 99+ intake will and is available cheaply, and a set of cams designed for the improved flow of the TFS heads will give you AT LEAST 60rwhp on an NPI car after it's tuned. You can't just buy the heads and bolt them on to your '98, but if you do it right, the gains are astronomical compared to any other mod (except power adder) on the NPI car.
A good combo:
PI intake from a '99+
Modular Headshop Stage 2 TFS specific cams
FRPP head change kit (bolts and gaskets)
A good dynotune
This would be worth AT LEAST 320rwhp with longtube headers, and that's a low estimate, since that's what you get with a PI engine with lower compression. The raised compression using the NPI block should give you quite an increase over those numbers.