Hello, long story short, I have a 99 F250 4x4 V10, with a blown up motor. I got a very low miles engine out of a F53 chassis, swapped the parts to drop it in the truck. I am new to the V10 world and apparently there are a W head and a PI head. My question is, are the intakes different? My new motor is a W head, will the PI intake fit and work or do I have to use a different intake? I know this may be a common question, but I don't have time to go threw all the V10 threads to find the info I need. Thanks for any help!

 

What year model is the F53?
Yes they are different. Although the early ones have a W stamp I haven't ever heard anyone call it a W head, most refer to the early ones as non-PI. The W stands for Windsor which is the plant where the truck 5.4 V8 and 6.8 V10 engines are made.

Stamped in the part number of the head just above the exhaust ports, the early non PI heads will say "6.8L W" on the top line and the second line will be a long part #.
It means Windsor.

The later PI heads will have the letters PI conspicuously stamped in the part number of the head just above the exhaust ports.
It means
Power
Improved
They made more power, which was such a noteworthy improvement that Ford designated the heads as such in the part # stamping.

Also, the chambers and port runners are different volume, the intake ports are a different shape, the pistons have a different shape.
If you want to tune it and get the most out of stock off the shelf V10 parts, you would put a set of PI heads on your early non PI short block along with the PI intake. This will net a small but noticeable compression boost as the early piston will make more compression in a PI head than the PI piston. I am sure someone will correct me or add specific specs and part numbers but that is the gist of it.
Different intake ports, the older intake manifold will not match the PI head ports.
Your 1999 F250 was not originally equipped with PI heads so unless the F53 does have PI heads you have nothing to worry about, just swap the external parts you need like oil pan and dipstick tube and exchange engines. It is basically a long block swap unless your F53 engine has PI heads. In either case you should keep the F53 intake on it unless you want new intake gaskets, which is a good idea at this point since they are easier to reach than with the engine installed in the truck.
You're welcome.

 

Best I can see is someone has changed the motor in my truck from non-PI to PI engine or head swap. Unfortunately I don't have a non-Pi I take and don't know a part# to begin looking for one. My F53 was a 1999. Thanks for any help!

 

car-parts.com

You're going to notice a difference in power, as in less.