since buying my fx4 i have found out that most of the aftermarket exhaust options are for the 5.4. i have heard that dynatech's longtubes for a 5.4 can be used on a 4.6. does anybody have any info on the mods which need to be made for the installation?

 

Well I just typed a book on this subject with pictures and it timed out and I lost the whole thing! I have to go make some more coffee! lol

 

Ok, here we go again. First of all, it can be done! I will post the pictures first!






Here is the short version of my book! lol First, the heads on the 4.6L and the 5.4L are the same. Where you run into trouble is the deck height difference. You will have to clearance the starter on the right side. I had to cut and reweld one tube on the left side and The EGR tube on the 98 4.6L is a smaller diameter and has a smaller nut than the fitting on the Dynatech. So, I went to Ford and bought a Lightning EGR tube and cut the bottom of it off. I cut the bottom off of the 4.6L tube and welded these together. Problem solved. I will be around to answer you questions.

 

Hey Flats Man, can you stick a 5.4 crank and rods in it and make it a 5.4L? If so, now would be the time to do it...

 

Nope, that wouldn't work because of the deck height difference. You can Stroke a 4.6L to over 5.0 Liters with some of the stroker kits that are out there.

 

hey flats...you said you had to clearance the starter. did you dimple your primary header tube or were you able to shave the starter case???

 

I did my truck so long ago that I really can't remember all the details on it. I will put it up on my lift and try to get you all some detailed pictures of the install this next week. I will take pictures of the truck the way it sets right now.