97 4.6L vs. 99-present 4.6L

[FordMAN7791]

Does anyone know what exactly Ford did to gain the horse power from 98 to 99? I am curious because I have a smashed 99 with the 4.6 and I just bought a 97 that may need an engine so I wanted to know if there were going to be any problems with the swap? If it was just in the CPU, could I swap that as well to get the better performance?

I have cracked Exhaust Manifold on the 97 and was going to replace it with headers, any suggestions?

Thanks
Mike

97 XLT 4.6L
99 XLT 4.6L (Parts Vehicle now, thanks to the wife)
99 EB 5.4L

 

[mmrseed]

I don't know what the hp rating is for each and how different they are but in '99 ford started using the PI heads on the 4.6L in the mustang GT which boosted it from 220 to 260. It is possible they used it also in the expy (I'm pretty sure they would). But if there is only a slight diff between 97 and above then I would guess it is a reworked intake manifold or revised throttle body that produced the change. Anyone else?

 

[walnuts4x4]

I believe the only difference is the PI heads... I don't remember the year they changed them but that is the main difference

 

[panda24619]

from what i remember it was the cpu. the did that to increase hp and trq without losing any mpg. but it could be something else.

 

[trippn01]

i dont think it was 99 they changed the heads...if i recall my stock expy is only pullin 220 hp

 

[FordMAN7791]

I don't usually like to reference Wikipedia but according to them the horse power changed from 1998 to 1999 by 25 HP but doesn't list what was changed. If it was the heads, then the increased HP would come over to the 97 with the swap however, it they increased the HP with CPU then I would have to move it over and hopefully the wire harness is the same.


This is the info that I pulled from Wiki:
Engine Years Power
4.6 L (281 cu in) Modular V8 1997-98 215 hp (160 kW)
1999–2002 240 hp (179 kW)
5.4 L (330 cu in) Triton V8 1997-98 230 hp (172 kW)
1999–2002 260 hp (194 kW)

 

[mmrseed]

If it really increased that much then it is surely because of the PI heads Ford started using on the 4.6L V8s in 99.