Does anyone have any suggestions on taking off my stock manifold and exhaust and replacing them with headers and dual exhaust. Are the headers reallynecessary to get some extra power or can i just keep the stock manifolds on and get good results. Any suggestions on make and type? Do I still have to run with the cat?

thanks

 

It would help to know what year your truck is, but 460 engines have long been hampered by restrictive exhaust ports in relation to their intake ports. Anything you do to help them "breathe" better on the exhaust side makes a difference!

Hedman Hedders makes a set of affordable headers for your truck (again, depending on year, but going by your screen name I'm gonna guess it's a 1990, and Hedman has that covered under part #89340, which will fit your engine and chassis, but will NOT have provisions for an oxygen sensor or any emissions tubes). If your truck sports EFI, you would need to install an oxygen sensor bung in one of the header collectors and run a new oxygen sensor for your application (no use trying to 'save' an old one...just replace it).

After the headers, what you do will be determined largely by your budget, the sound level you're after, and whether or not you need to comply with local emissions laws. The catalytic convertr(s) can be retained, or eliminated...and the engine will run fine either way on a model that old (1996 and newer will tend to set a "check engine" light once they detrmine the cat is missing, due to the way their operating system works, with downstream HEGOs (Heated Oxygen Sensors). But this won't apply to a 1990).

I'd recommend running 2.5" diameter pipes with a quality turbo style muffler such as a Walker Dynomax or equivalent with an exhaust crossover (H-pipe) somewhere close behind the header collectors if possible...but the crossover is not absolutely neccessary if you don't want to spring for the additional expense, but it does help boost power in the lower RPM range in most cases. If it were me, I'd eliminate the cats, but that's just me talking...don't tell 'em I told ya so! Ha ha!!

 

As a side note, running new dual exhuast off the manifolds will help, and can save you the hassle and expense of installing headers. I've had several older F250s with the 400M and the 460 engines and most of them had duals run off the manifolds and they ran fine.

In addition to a cost and time savings, the exhaust manifolds tend to keep the motor a little quieter, they're less likely to develop annoying leaks that can be heard as a 'ticking' sound common to some header installations, and they often keep your truck a little easier to service...in some cases, access to the starter is limited with tubular headers, where the manifolds tend to clear it just fine.

You WILL often see improved performance and fuel mileage with headers, but in a street driven vehicle, the difference is fairly minimal and may or may not be worth the extra cost and hassle...but that's up to you. My last 78 F250 with a 460 ran real strong through manifolds and full duals with Dynomax mufflers and a crossover pipe, and I doubt that adding headers would have gained me a whole lot more. I used a 1971 intake manifold off of a 429 Mustang with a rebuilt and recalibrated GM Quadrajet (Ford used Quadrajets back in the early 70s also) for the best possible fuel economy and performance. It was a strong running truck that still managed to deliver an average of about 13mpg, which is pretty good for an old F250 with a big block, automatic and 4.10 or 4.11 gears in it!