Ok so my brother has 91 4.9L 300 I6 F150 4x4 efi W/ M5OD trans and 3.55 gears. If the 4.9L in it runs then me and him are going to do some small things to make it reliable and maybe get a little more power if not a 302 is going in it (that is what he wants).


Recently while looking for some other parts for it I found a 80-86 carbed 300 I6 with a one piece header not exhaust manifold at a junkyard. I looked at it very well and couldn't find any issues with it other then it could use a paint job.
Would that header fit this truck?
Would it increase power at all?
What is a used one probably worth?


I have no idea whom makes it I couldn't find any brands on it.
Trav

 

If its six pipes in one pipe out, its probably a Clifford header, google Clifford research.
It might make some power, but the general opinion is that the stock efi manifolds flow lots for these engines.
It should fit the efi motor, at most I would pay $75 for a used header, and you will have to weld in a threaded bung for the O2 sensor.

 

It did go 6 into 1.
Can't I weld the bung into the exhaust pipe?
If the stock ones flow fine then I will leave it I though maybe it was like the V8s. 6 bangers are really weird to me.
Trav