Sorry for asking but what are pi heads? i can get a whole engine from a 2004 crown vic is that better? and will it give me more horsepower than i have now? I want some more power cause after 3 she pretty much done. This car also has a 6spd tranny. was like that when i got it.
PI heads and intake are what's on '99-'04 Mustang and '01+ CrownVic/GrandMarquis/TownCar.
Your car was rated at 215hp. PI engines from a Mustang are rated at 260hp, and due to differences in the exhaust on CrownVic etc I think those were 240hp.
The two engines are identical except for exhaust manifolds and upper plenum; for the engine swap you would retain your current plenum and exhaust manifolds, front accessories like p/s and alternator, fuel rails and ignition and flywheel if you have a manual transmission. This is a direct bolt up, minimal BS swap; for the headaches involved in swapping heads on a 4.6 that's still in the car most would agree that just swapping the engine is easier.
The engines from CrownVic etc are generally more desireable for this swap as they tend to have lived easier lives than something from a Mustang.