I'm sure this topic has been beaten into the ground, but I am having trouble getting my headers to fit the passenger side of my truck. It is a 77 F100 with a 351W in it. I have the drivers side on, it wasn't too much trouble, only had to remove a valve cover to get it down there, lol, but the passenger side collector won't fit between the starter hub and frame. I have searched and not found anything on it on the forums, but I have heard that I should just cut the frame, and I have heard that I should just loosen motor mounts and try jacking the engine up to get it under there. The headers are Flowtech 12500FLT. What are your expert thoughts on the matter? Any information would be greatly appreciated, thank you.

 

This may not be the easy way but its better than cutting on your truck. If you unbolt the motor mounts and raze the front of the motor a little bit.

 

Ah, and that'll do the trick then?

 

That shoud do it. I have the same problem with my truck

 

If you want an easier way to do it, take out the starter and put the header and the starter in at the same time and it just slips right in, my buddy had the same issue with his motor and it was the easiest way to do it without lifting the motor....jmo

 

The difference in engine deck height or engine size between a 302 that the headers were designed for and a 351W may give you unavoidable clearance problems.

 

This is a fact, the issues with headers fitting just the way you want them are always gonna be there because they didn't come in the truck factory, it's just like the old saying goes....."things that are hard never go your way"

 

I have put headers on many Ford trucks both 302's and 351W's. What I do is loosen the motor mount bolt on the drivers side (dont take off all the way) and remove the motor mount bolt on the passenger side. Use a bottle jack and postition it so that when you jack up the motor that it lifts the passenger side up. you should then have no problems with the starter being on the motor. (the starter is not the issue it is the bulge in the bellhousing for the starter, as soon as you jack up the motor the header will fall into position)

Also I have modified my tranny cross member to deal with the issue of the headers "knocking" against the tranny crossmember



Wally Womack

 

After seeing so many posts about headers on our trucks (from 65-79) I dug through some of my old reciepts and paper work and found a VERY old instruction sheet from Cyclone Headers that I had installed on a 71 Ford truck with a 302 3 on the tree (about 23 years ago!!). I had to laugh after actually reading the instructions again this morning.......My suggestion DONT follow their instructions to the letter, Here are a few reasons why.

instruction #1 preparing truck for installation....

c. jack the truck up at least 2 foot, put solid supports under the frame.
f. remove starter
g. remove dipstick and dipstick tube ( now on this one you may have to actually do this depending on your oil pan )

instructions #3
install header on right side from below
a. remove crossmember below transmission (if it has been rivoted remove motor mount perch) (I have never seen one that is rivoted in place!)
c. reinstall crossmember or motor mount perch
d. reinstall starter and wires

instructions #4
install header on left side from below
a. remove crossmember below transmission (if it has been rivoted remove motor mount perch) (again I have never seen one that is rivoted in place!)
c. reinstall crossmember or motor mount perch

(If you had the crossmember out once already why did you reinstall it if you will be taking it right back out for the other side????)


The driver side header will fall into place from above there is NO reason to try to install it from below!!!

also do not jack your truck up in the air 2 foot unless you are 8 foot tall LOL

DO NOT REMOVE YOUR PERCH MOUNTS....there is no need for this at all!!!

Like I stated above there is a much easier way to install headers than by following the instructions that come with them.

Wally Womack

 

Wally, since you say you have lots of header experience in these trucks, what headers have you used with 351w in 73-79s?

 

I prefer Cyclone and Hedman headers. I have used hooker headers before but did not like them because they were such small primaries. and small collectors
(these were the cheaper set not super comp. ll. If I had the money that is what I would use!)

Wally Womack

 

How are they for clearance with a 351w? (since they're designed for a 302)

 

loadfords


Installing 302 headers on a 351w the only clearance issue I have had ,was the
small crossmember that runs across from radius arm to arm it is a litle close, but no more that on a 302 I have put a small notch in some on the pass/ side
but not always an issue,the other thing would be that some times one header tube is a litle close to the (manual streering box) but if you bolt the drivers
header up first, and then loosen the one driver side motor mount nut, then remove the pass/side motor mount nut and place bottle jack down on lower
lip of frame rail and let it lean over to the motor and start jacking it up, till the
header falls in on pass/side, if the steering box is to close you now have (''dimpled it right where it needs it!'') keep a watch to make sure the drivers/side tube that is in ( ? ) does not dimple to much, if it does you may want to put your jack on a small stack of wood stacked on the ground so it will jack it up straiter on pass/side. be sure that you don't jack the motor on any thing that it will mess up!

The trans crossmember is an issue with
302 or 351w header pipes, I have ran the header pipes low for years, and you
do get tired of hearing it bang on the trans crossmember!


Wally Womack

 

I appreciate the information gentlemen, and I will use the knowledge you have bestowed upon me to install my headers.(or at least try my damnedest)
Thanks guys.