I have a 79 F-150 Regular Cab, Long Bed, 2wd, Automatic with a 351M. I'm going to be doing a conversion to a 400M, and I also want to switch from the standard exhaust manifold that it has now, to headers and dual exhaust. I was wondering if anyone here has recommendations on a brand or set of headers? I'd hate to waste money buying poor ones or the wrong ones. Thanks for any advice you can give!

 

I can't recommend headers because the Doug Thorley headers I have are no longer available, but if you do get headers make sure they are ceramic coated. They run cooler than stock cast iron manifolds. Painted headers will rust in a few months and you will be sick of them.

 

hey there i cant suggest any headers but when you get your 400 in posta threat becuce i just put a set of hedman headers on my 76 f250 4x4 with a 400 it was a hard job put i will post more about what i hade to work around to fit them in

 

You get what you pay for with headers.

 

i had a set of flowtech headers on my F250.. they fit great and they're pretty cheap

 

My friend is restoring a 78ford 4wd. 400 ford with australian heads. On his header he ordered some headers from a restoration mag and they look awesome. The truck is a original type restoration very clean, but with a few modern upgrades like a MSD and modern carb. As soon as I find out brand and they were jet hot coated and looked very nice/very clean. Be sure to look at some of those truck restoration type company's good info and some cool products. Get back with you later on this.

 

Same truck as yours exc 4wd. I built to 408cid, milled the heads .030" (DONT do that, I ended up at 9.6cr which is too high for the open chambers. Don't go over 9.0cr, aim for about 8.8cr for these open chambers, cast pistons, open heat crossover, etc in a heavy truck).

Also ported the exhaust roof as best I could (get rid of the thermactor bumps). Ran a 204-214-112-.484-.510 cam, and both Performer EGR and Weiand Action Plus intakes. Performer EGR gave up maybe 5hp up high but gained at least that down low, and made it CA legal when we moved there so it got the nod.

On top was either the stock 2v and snorkel air cleaner (that hot snorkel killed off about 15 net hp), or 600cfm Autolite 4300 or 600cfm Holley or 750cfm Holley. The 750 was stronger on top, the 600 Holley strongest overall, 0-60mph about 0.1sec faster than the Autolite, but with the Autolite I'd get 13mpg highway which was excellent for this 5400 lb rig. The engine itself was about as strong as a Ford 390gt with headers, then again it's a similar build.

If you can, I'd scrounge some 351c4v heads (but then ?? on the header port fit) or Aussie heads or the $$$$ Edel heads. The open chambers in the 400/351m are awful for pinging, weak point of the engine. The 429/460 ran full open chambers for one year (1972) and then went back to a quench design. Other than that the 351m/400 is a great street engine.

You probably know this but avoid the dreaded aluminum oil pump, make sure you get an iron one.

One thing on the Hedmans, the pass side aims kinda tight at one of the x-members (at least on my 4x4), no sweat for the muff shop but on a do-it-yourself exhaust it would be a pain. I used 2-1/2" pipes and TurboSonics, aka Walker superturbos.

With the stock 2v, this rig passed CA smog with flying colors, smogged cleaner than many of the import cars in front of it. Good combo.

 

Fel-Pro makes head gasket spacers that are .041" thick just for this purpose if you mill your heads and it's too tight Part number is 8347-SP, fits most if not all 351M and 400 engines.

 

I've always run Hooker Competition from header to tailpipe on my F150. I've never ceramikoted or header taped them, and other than a little bit of increased under-hood temp, they've lasted fine in just paint. In 26 years, the headers have been replaced twice, the pipes/muffler setup from collector back three times. Not all that bad for nearly 3 decades. Good performance, good sound with their turbo mufflers.

 

my friend kurt is restoring a 79 ford with 400 austrailian heads. He has sanderson headers and they fit nice. I forgot the numbers but look up sanderson headers and you'll figure it out. sorry I took so long been working.