300 at the crank is a stretch, stuff like underdrives and TB/plenums really don't do squat, and while kooks will open things up, the scavenging benefits of longer headers won't be fully utilized with a stock PI cam with little overlap, so all you get is the flow, which really ported manifolds are adequate at.
Personally I'd just do a full motor swap rather than the headswap. The newer motors have everything you need INCLUDING the valley tube(I ran the Crown Vic one for years), have better components like the crank sprocket/trigger wheel, and you can just flip the plenum/throttle body around.While you're there you can put on all new gaskets and seals in otherwise inaccessible areas as well, which is really nice down the road. All you'd have to source, which you would regardless, would be the intake tube, EGR tube and vacuum lines off a 96/7 tbird, and if you want to save the hassle of swapping fuel lines under the fender, use fuel rails from a 96-97 Crown Vic/Grand Marquis. Swapping heads with the block in the car sucks ass. I love compression, but I dislike leaky tired short blocks, and really dislike guiding a 40 lb cylinder head with a weird shaped tube into a hole two feet below.
Last edited by XR7-4.6; 03-02-2016 at 02:30 PM.