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View Full Version : Fender well or full length headers


jmoore704
December 1st, 2011, 08:23 PM
I'm looking at replacing the old exhaust system on the 79 F250 4x4. I really like the idea of running the exshaust on the outside of the frame and keeping the heat away from the tranny and starter. From what I can tell by looking underneath the truck it would be a better cost effective and agervation option. I would like to eventually run 12in wide rims and wonder about tire clearence. Any help with anyones experience would be greatly appreciated.

JSoko
December 1st, 2011, 10:10 PM
I dont like the idea of going to the outside of the frame, because you will have to go low to clear the frame, thus cause a place where you have lowered your ground clearance and you will at one time or another snage something
clearing the starter will also be a problem, you can get a heat blanket/shield for the starter, but I use sheet metal around the starter and 4 metal tube spacer wired around the exhaust pipe and cover with the sheet metal; this will allow air to flow around the starter and pipe keeping both cool
be sure not to ground out the HOT wire on the starter

full length headers would be my choice

BigBlue79
December 1st, 2011, 11:22 PM
I have heard so much debate between this, first off Jmoore what engine in the 250 351m or 400, 460's didn't start in 250 4x4's until 1983.

Second, my knowledge of this subject is as follows, putting on longtube headers(Full Length) will put the end of the header almost where the crossmember is for the tranny, some guys have ran the pipe over the crossmember some have ran them under the crossmember I personally prefer to run the pipes like stock but w/ out the Y-Pipe leave the driverside crossover and run both pipes inbetween the frame rails down the passengerside then either dump them there or run them over the axle out back or angle them one kicked out of the p-side and one run over the d-shaft and kicked out the d-side both begind the tires like this:
http://www.fordtruckclub.net/forum/photopost/files/1/2/4/9/1986_bronco_xlt_032small.jpg
, use 2 1/2" pipes and stainless if you can afford it, round it out w/ some nice glasspacks or turbo's to make the M Block sound nice.

Running the pipes under the frame is a no no, if you hit a deep pothole or go offroading think what would happen if you were to bottom out or hit a huge azz rock.. What I posted above is what was done on my old Blue F150 but w/ out headers, If I remember right fenderwell(Chassis Exit) headers don't like these old trucks.

Also, Gasket Match the headers to the exhaust gaskets make em flow a little better.

JSoko
December 2nd, 2011, 08:49 AM
Yes, long tube headers on my '77 F150 with Windsor engine; the center of collector flange came to within about 8 inches of the crossmember, I made an off-set by fabricating (2) 45 degree bends welded together. I still had to notch the crossmember to go over the top.
Keep in mind that each change of direction causes a restriction of the exhaust flow.

H & X pipes are still, in my mind up for debate, I have always run true duals; even though science says the scavenging effects of the H & Y add to performance

JSoko
December 6th, 2011, 04:30 AM
I dont know whos theses are, but heres some pics of a good install
as you can see they went over the cross member without useing much of an offset (see top right pic)

http://www.facebook.com/media/set/?set=a.10150373195456598.376454.93322096597&type=1

I hope jmoore is coming back soon

BigBlue79
December 6th, 2011, 09:16 AM
I hope we didn't scare him away. :hide:

JSoko
December 6th, 2011, 10:41 AM
unlike many that never return to read the post after you've spent some finger work trying to help with info, he has 7 post; could be that alot of folks will get scarce during the Holidays

just remember what we post helps others and becomes a link to our site through the internet

keep up the good work Ken

Russo2
December 6th, 2011, 02:23 PM
I dont know whos theses are, but heres some pics of a good install
as you can see they went over the cross member without useing much of an offset (see top right pic)

http://www.facebook.com/media/set/?set=a.10150373195456598.376454.93322096597&type=1

I hope jmoore is coming back soon

That is our fearless webmasters flareside getting that exhaust job.

JSoko
December 6th, 2011, 05:09 PM
he's got it going on