Are there any hp and/or torque differences between a 1997 4.6L and a 2002 4.6L?

 

Don't know the exact numbers but the big difference is the heads. The 97' has non performance improved heads and the '02 has performance improved heads.

 

Yep. The pre '01 4.6's made 220hp/265tq, in '01 and later they made 231hp/293tq.

 

HI!... "P.I" = Power Improved............

 

I've been reading about these "Performance Improved" heads, and I was wondering where the best place to buy them would be... Should I check Ebay (always sketchy with parts) or go online and search around, or go to the junkyard and hope for an 02-current (?) 4.6l, and try to finaggle a deal? I think i also read somewhere that the heads were only in 02 or something, but im not sure... anybody?

 

HI!... "P.I" = Power Improved............

 

In 97 hp was 220 and 293 foot pounds torque did not change at all with the new heads.PI heads were only good for 11hp and were nothing more than a mid model marketing ploy.
Ported NPI heads flow better than factory PI units.If you can get a good NPI truck with out coil over plug(cop)ignition go for it as they are for more trouble free.Plug change on a 98 non cop motor is half the price of a 99 and up cop motor,all for an 11hp gain.
IMHO 98 and 01 trough 04 are the best years for the heritage style truck since the bugs were worked out.I never buy a first year run after change to a platform.Best year all around is 98.
cheers

 

How is that???



BTW, the 4.6 got both the COPS and PI heas in 01

 

I have an 07 with a 4.6 and it now has 248hp. I can't remember the torque numbers though. It is still a dog though. LOL

 

Mid 99 is when Windsor started using the new heads and i know Romeo got them first.I was there for the machine build.As for the ported and polished NPI heads out flowing stock PI heads I've heard this many times.I've had a 97,98 and 2002 and the earlier motors are far cheaper and easier to work on.

 

Only the 5.4s got the PIs in 99 In the trucks anyway.


NPI ported head easily outflow stock PI head, you are correct there

 

HI!... And a ported "P.I" head out flows a NPI head.... so.....

 

Also in 1997 they used a heavier fan clutch, and steel fan blades, so you have even more parasitic loss there too.

 

yep lol my stock fan was a heavy sun bich