Engine and modification question

I have a 97 f-150 extx. cab 4.6L v8. Its been the best vehicle by far that ive ever owned. Got about 110k on it and its never had one problem with it. Since its 2 wheel drive ive always kinda wanted to make it a sleeper. I currently have a K&N cold air intake, throttle body spacer, diablosport performance chip, and a performance exhaust system. I was wondering if u guys knew of any other good mods to make other than forced induction. I know its getting on up there in mileage so i also wondered if the mustang gt 4.6l v8 would run right in my truck or maybe even the cobra motor. Thanks for all the help.

Headers will help a lot, and a air filter/MAF assembly from a 5.4L will too. The CAI is over-rated. Next comes major engine work, like ported heads which would be worth some SERIOUS power (40-60 RWHP).

Tuning on these is HUGE. The folks at SuperChips Custome Tuning offer the BEST DIY package out there, but you gotta want to tinjer with your EEC yourself. If you only want a chip, then the BEST (same info different source) is Fordchip dot com.