I have a 92 f150 4x4 reg s/b with a 351.I am planning to improve the exhuast system.I live in Vancouver Canada and the emmission laws are strict.The truck has had problems with the exhuast manifold before I owned it.I have been given the impression that excessive heat causes the problems.I hope to fix the problem by installing mac shorty headers and a 3" system free flow cat and muffler.The existing system is factory from the manifold to cats but a restrictive 21\4 muffler with single outlet is in place of the dual outlet factory unit.I am looking for any input good or bad concerning my plans or impressions.I do realize that the truck will sound a little more aggressive and I hope this to be a pleasent side effect.I do not expect any noticeable fuel consumption improvement or hp gain.


ford trucks love to work and play

 

I've never used Mac's truck headers but I have a set of their shorties on my Mustang. Good set of headers for the money. The only issue I had with them was the fit around the steering shaft but a couple of minutes on the shaft with a grinder fixed that. The HTS coating they use will cure after you start it up. NOTE: It makes a smokey mess the first time, do it outside. The rest of your set-up sounds good.

Rodger

 

Hey djblue. i live in richmond bc and have an 88 f250 with a 351. when i looked into headers the only ones i could find were from JBA. this was due mainly to the "Dual air-port injection". you know those little pipes that run from the intake to each exhaust port on the manifold. there was also the issue of 4x4 for some reason as well. because they were so expensive and my exhaust manifold leak turned out to be just a lose bolt, what i did is put a 3" stainless from the "Y" all the way out with a high flow cat and muffler. it sounds great and runs better. cost $860.00 i believe and was a really sweet job. The headers were gonna be another $1000 i think so i left them alone till i do an engine rebuild with possibly different heads.
anyway i wanted to tell you to be real careful with header selection cause there are apparently issues with under-hood temperatures and chronic leaks so really good quality headers are the only way to go.
can you let me know what mac headers are like, how much they cost and if they will fit my truck?

thanks,

rusty.

 

I have been running the Mac equal length shorty's on my 5.0 for a while. I like them alot, I had JBA's on it before, but the JBA's would not fit the new heads I put on because of the spark plug angle. The macs fit fine. JBA's are a higher quality product, but the Macs are well worth the price. I say use them. Thats my 2c's.