you can use any year block up to 03. After that they went 3v and the motor mounts changed from what I gather. I used a 2000 expedition motor as a donor and replaced the rods and pistons with forged goodies, added some performance bearings and ARP hardware. Bolted on a set of PI heads and dropped it in.
Ported heads are only so-so in this application until there's longtubes and hotter cams in the mix. I'm having a set made now that might just yet make it to full production.
You can drop a 5.4 into any 96-04 mustang with this intake. It'll also work for other cars like the CV's and even trucks with minor mods to existing accessories (egr, plumbing, etc...)
I should have my car out of longtube header jail friday. Dyno numbers soon to come.