what is the diff between the 98 and 99 5.4??
 

Hi,

This is my first time to this site, I just bought my first ford 2 days ago, and so far I love the truck. Even though I have a chevy also, chevy trucks aren't as good as the fords, :) .

I bought the 98 because it had everything I wanted, and was in excellent shape. Just that it's a 98, I know they have less power then the 99+. My question is what did Ford change in the 99+, is it new pistons and a cam?? Exhaust?? I am just wondering if the hp on the 98 can be upgraded to the level of the 99+ with Ford parts. My camaro is modded and I want to keep the Ford truck pretty much stock, so I don't want to throw in a big cam and deal with gas mileage issues and so forth. Thanks a bunch, and merry christmas.

Brian

HI!... The "99" and up F-150's with the 5.4 got "P.I" (power improved) cylinder heads, the F-250 with 5.4 got the same heads in "2000" , and the MUSTANG GT 4.6 also got them in "99". In "99" Ford installed the "P.I" heads, "P.I" intake manifold on the 5.4. The MUSTANG GT 4.6 got the same but with higher lift cams. It makes the same H.P as the "P.I" 5.4 but no where close to the TQ. Here's a few pics of a NON "P.I" head (97-98) and the new "P.I" head. You can see that the intake runner is totally differently shaped. A non "P.I" intake WILL NOT bolt on to a set of "P.I" heads. Both year 5.4's have 9.0:1 compression but use different pistons due to the smaller cumbustion chamber on the "P.I" heads. If you bolt a "P.I" head on to a NON "P.I" 5.4 engine, your compression ratio will raise to about 10.5:1. This would be good for a N/A application but NO GOOD if you plan to supercharge it then or in the future. You also would have to watch how radical you go on the cams, because you will run into valve to piston issues more so on a head swap. The pistons in a NON "P.I" 5.4 engine are less dished than the pistons in the "P.I" 5.4.

https://www.f150online.com/galleries...4-794-6999.jpg
https://www.f150online.com/galleries...4-794-7045.jpg
https://www.f150online.com/galleries...4-794-7046.jpg

There are more pics of the two style heads in my GALLERY in the link below.

Welcome to the board!!

The only real difference (Which I learned here!) is that the '99 has "PI" heads (power improved) do a search for "PI" heads and Neal and you will see pictures and a good written discription about the differences.

From what I understand there are no other real differences. so if you want the same hp as the '98 you will need to swap heads and from what I understand the new heads are upwards of $1500 each (not installed)

enjoy your truck!

Neal must have been typing while I was!!!!:rocker:

thanks guys.

you guys really know your stuff! $1500 for each head is alot of money, I think I can live with the hp I have for now, :). The truck still has some low end grunt though, this thing rocks.

I paid just under $800 for a pair of new complete 98 heads from Ford. I would find it highly unlikely that you'd have to pay $1500 per PI head. Shoot...the 99 DOHC heads are just a hair over a grand per complete head, and there is a lot more to em.

Plus, you'd need an intake from a 99+. If I knew then, what I know now, I would have done the swap when I replaced the heads for my rebuild.

hmm, $800 for heads?? Maybe I will end up modding this thing, :rocker: . I can't help myself sometimes...... :)
Thanks guys, I have to get out and drive my truck now
:thumbsup:


Brian