Interchangeable heads?
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Interchangeable heads?
One of my buddies told me last week that if I could find the heads off of a 5.4l Triton motor, that I could swap them out onto my 4.6l Triton and get a 
load of torque out of the swap? is this true? And if so, how difficult is the job of swapping the heads?
load of torque out of the swap? is this true? And if so, how difficult is the job of swapping the heads?
Senior Member
Joined: Sep 2011
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Depends on the year of the motor you get the heads off of. If they are 99+ 5.4 2v/01+ 4.6 2v there will be a performance increase. You will also need a intake manifold for you size engine i the same year range of the heads.
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Joined: Feb 2011
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From: MD
That's also assuming your truck is 97-2000. If it's a 2001+ you already have the PI heads. 5.4l and 4.6l motors use the same exact heads, there's just two different models of modular heads, PI is power improved, which like he said 4.6l got in 01 and 5.4s got in 99.
There's a lot of side effects to the PI swap to consider and if your truck is a daily driver I wouldn't recommend doing it.
http://mustangforums.com/forum/4-6l-...d-to-know.html
I used that write up mostly and looked at others as well to compare information, but that one is pretty good. Also you'll want to read http://www.therangerstation.com/Maga...0/Ford_4-6.htm
That article to help you learn more about the different versions of the modular motor.
Custom tunes and at least 89, should probably do higher, octane is required for the swap for the engine to run right. The reason is your compression goes from 9.2ish:1 to 10.3ish:1 so 87 will spark knock. It's not bad under like 3 grand but in the higher RPMs it gets a lot worse and causes some serious damage. It's not too bad of a swap, but it's not exactly simple either, don't expect to get it done in a weekend and have to drive to work monday. If you don't have another vehicle to drive I wouldn't recommend doing it for that reason, plus the cost of gas goes up and MPGs go down with the swap so driving it every day can be expensive.
There's a lot of side effects to the PI swap to consider and if your truck is a daily driver I wouldn't recommend doing it.
http://mustangforums.com/forum/4-6l-...d-to-know.html
I used that write up mostly and looked at others as well to compare information, but that one is pretty good. Also you'll want to read http://www.therangerstation.com/Maga...0/Ford_4-6.htm
That article to help you learn more about the different versions of the modular motor.
Custom tunes and at least 89, should probably do higher, octane is required for the swap for the engine to run right. The reason is your compression goes from 9.2ish:1 to 10.3ish:1 so 87 will spark knock. It's not bad under like 3 grand but in the higher RPMs it gets a lot worse and causes some serious damage. It's not too bad of a swap, but it's not exactly simple either, don't expect to get it done in a weekend and have to drive to work monday. If you don't have another vehicle to drive I wouldn't recommend doing it for that reason, plus the cost of gas goes up and MPGs go down with the swap so driving it every day can be expensive.
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Joined: Sep 2011
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I had a NPI shortblock, with PI heads. I can attest to the bad fuel economy and not being a good daily driver.. The PI equipped trucks have different transmissions along with different gear ratios. I currently have a cammed PI 5.4 that came from a 03. Having lower compression allows the engine to run with full timing on premium. When I had the PI swapped 5.4 it could only run a maximum of 25 degrees of timing on pump gas because of knock. My cammed PI engine runs 37 degrees of timing on 93.