Hi guys. My dual exhaust has rusted off on one side, and so it's time to replace the whole system. I've got an 86 F-150, 2WD with a 351 C under the hood. The system that came with the truck when I bought it was made up of, front to rear...

Headers >>>>>>>>>cats>>mufflers


...with the whole system dumping out in front of the rear tires. The cats were pretty far back along the line, right in front of the mufflers which were the end of the line. Now, I'm honestly not sure if that setup is good for performace, but I was always under the impression that the cats had to be near the headers so they could reach sufficient operating temperature to work properly. Correct?



Anyway, I basically want to replace what I had, but configured for optimum performance. I'm keeping the headers, so the question is, where in line would be the best place for the cats? Right off the headers, or back further? How close to the cats would I want to place the mufflers?


Last question....does anyone have a recommendation for a good (or at least decent) performance oriented Cat?



I like to drive my truck hard, but as it's a 2WD I only really use it on-road, if that helps.



Thanks in advance for your patience and your advice, guys.



Rob.

 

Thats kind of a wierd setup. The cats will warm up a lot quicker being closer to the headers. I would put them as close as possible.

Catco, Magnaflow, and others have cats that will flow better than factory.

 

Excellent. Thank you very much.



Rob.

 

Cats, skin 'em! Check out CarSound high flow cats and run them just after the headers. Between gutted and CarSounds (2 cats) on a 278" motor I couldn't tell the difference, they flow. On smog test, 5 of 100 and 5 of 180 ppm HC.

Carl....=o&o>....

 

I'd say if you didn't have to worry about emissions laws, just get rid of those cats....

If you need to run them, like the others have said, they should be right after the headers.