i read somthing that you could swap the heads on a 4.6 for the heads on a 5.4 and get about the same performance. what would this intale? also can you swap the heads off a 4.6 SHOC for the heads on a 4.6 DOHC? and if you can, how hard is it and what do you have to change? i have a 1997 F150 4.6 SOHC 4x2 extended cab. i plan to had a supercharger also.

 

Adding higher compression heads to an engine and then putting a supercharger on will probably toast your motor. I'm pretty sure JMC already explained this in one of your other posts. If perfromance is what your after then you should talk to Mike Troyer. Take a look in the computer chips forum. Give him a call or check out his website: http://www.troyerperformance.com Take a look at his stage 5 kit (if you want a s/c).

 

To increase the power you will need the heads from a 99+ 5.4 Triton or a 2001+ 4.6 Triton or what are called the PI heads. The Combustion Chamber on the Non-PI heads that you have on your truck now are 52cc's and the PI heads are 49. This will increase your Compression Ratio to about 10.5:1. That is too high for a supercharger. The Lightnings are around 8.5:1. So if you are planning on Supercharging you will need to reduce the piston hight in order to lower the Compression Ratio. The Lightning has dished pistons. FYI The PI heads are used on Blocks with dished pistons also, but not as pronounced as the Lightnings.
So to be able to safely supercharge your engine after the head swap you will have to open up the engine and swap pistons or run substantially less boost on your Supercharger. Now having said all this to change the heads you are looking at about 8-20 hours of work depending on how skilled you are. If you still wish to swap heads I would recommend you invest in a shop manual as it will be required to do the work. You might want to talk to your local dealer and ask them to look up the time allotted to do the swap. Just so you know;
The exhaust manifolds must be removed, The alternator, The intake maniforl (btw it has to be replaced with a newer one from a 2001+ 4.6) the front cover, the timing chains, the head bolts are torque to yield so you throw them away. There are a bunch more of things involved but I don't have the proper frame of mind today to list them here. I don't wish to discorage you in doing this but unless you are handy with a wrench don't do it your self. I have a set of PI heads in my basement that are awaiting the cash to have them ported and get new cams. I will be installing them my self and in a way I am glad that I don't have the cash on hand right away.

Regards

Jean Marc Chartier

PS. I forgot to tell you that for the DOHC heads you will need new timing chains, front cover and intake manifold at the very least.

 

well i race with a couple of guys that have every tool know to man in there garage, except a computer port readerand they would help me do it for free, they themeseleves are building a 583 hp 383 stroker for their malibu that will cost them about $3K and if they bought it complete it would cost them atleast $8k, i thought about building an engine like that, except it would be hard to pass texas emmisions. Would it just be easier to just put in a new cam and a supercharger , maby a set of headders and a new mantifold to try to get the power i want instead of swithching out the heads and pistons?