Having a hard time deciding.

[Hammer]

320 HP at the flywheel or at the wheels?

If it's at the flywheel, I would say you could get pretty close...

Other than the crappy 96-98 intake, there's really not a weak link in the engine.... (We won't talk about the deceased T-45 as I'm currently waiting for my Tremec TKO...)

Change out the cylinder heads and and intake with some ported PI heads and Bullit intake, you're looking at around 270 hp for the 96-98. Cams might be good for another 15hp (285)

Between some cold air, MAF, full exhaust... you'd get pretty close to 320.

The problem is the expense of the parts... they're not cheap...

The Saleen 281 would probably get to 320 N/A a bit cheaper.

But to be honest, if you're going with a modular.... a blower is a way to go. The engines (with good heads) just respond INSANELY well with relatively low boost.

For you, I would recommend a roots style blower on a 96-98 with a good set of ported heads. Runs just fine as a daily driver...

If you're really looking at cash flow, (I hate to say this), the 94-95 with the 5.0 will be the better choice as the parts are just SO much cheaper...