Does anybody know if the new heads off the newer 5.4 engine will fit the block on a 1999 5.4? I have a 99 f250 with 150,000 on the odometer and have started thinking about a rebuild. I think the compression ratio is higher for the 99 5.4 and was just wondering how the newer heads would perform. If someone has an ideal for better heads please let me know. The truck has a 6 inch lift with 35" tires. Gear ratio 4:10. I am interested in low to mid range torque.

 

Sorry, guess i posted this in the wrong area.

 

If you are talking about the newer PI heads they should bolt right on. If you are talking about the 3V heads, don't even think about it. You need alot to do a swap like that. PI heads and manifold would be the way to go. If you pick up a MM&FF magazine you can see alot of 4.6L head swaps which are the same thing. You could also just get some machine work done on what ya got to get the improvements you are looking for.

 

Thanks, I was thinking of the 3v heads. I was thinking the block was the same and they would bolt on. I will look at the other options. Thanks again for the feedback.

 

Physically i think they would bolt on but need so much else to make them work. There is a lot of new technology that will need to be caried over to your truck.

 

Can you explain the difference in the older heads, that I assume I have, and the PI heads. I looked at mine and did not see any PI mark on the front of them. Do the PI heads have the problem with blowing out spark plugs? How could my current heads be improved for a little more torque and hp? Sorry for all the questions, but i have found that I can get intelligent answers from this forum.

 

I'm sure you can find better info in the 4.6 & 5.4 forum. I am a V10 owner. Basically the whole modular family got "PI" or power improvments in 2000 I think it was. I believe that there is a PI marking on the newer engines. Basically all your old engine/power bldg things work, such as port and polish the heads. Cams are available for the 4.6 and 5.4. Check out that other forum Im sure there is tons of info in there. Good luck.

One last thing the spark plug problems are across the entire mod. family of engines. Blowing out plugs is pretty rare though.

 

sometime in 03 they improved the treads i think they went from 4 to 8 treads in the plug holes.

 

How is the hunt for info coming? Have you checked the other forums? Let me know.

 

Head work (ie, port-n-polish) would freshen it up almost back to new. Add a OEM direct replacement cam or a slightly hotter cam, and you're good to go! You can get away with just the head work though; it'd be a HECKUVA lot cheaper, too.

As mentioned, please do let us know what you find out and which way you go.

Daryl

PS- is 150K miles "time" to change cams/heads??? Or is this just you wanting that "punch" back in the motor??? Just curious... DS

 

I searched the other forums and think the way to go is to just "refurbish" my current heads. To be honest, the truck is still running great, has not started to burn any oil. I use it fairly hard, no towing, but a lot of offroading. I have not had to do anything with it except for a spark plug change at 140,000 miles (they were still the originals, and there was not much left of them). I change the oil every 5000 miles with a synthetic blend and the old oil still looks good so i don't think I am getting any blow by at the rings. I was just trying to figure out the best course of action for when i do rebuild. I am not really sure about the lifespan of these engines but it seems to be quite long. I am thinking I will need to rebuild at 250,000, excluding any unforseen problems. Thanks for all the info.