Are custom fit headers designed to bolt up to the rest of the stock exhaust? If not, do you need to have the exhaust custom made? Also, is it silly to run headers with single pipe/stock exhaust? Thanks.

 

there are different kinds of headers . stock replacement and longtube headers. stock replacement or shorties would be your best bet with little to know modifications needed. some times the Y pipe needs to be messed with a little but any local shop can make the minor adjustments for cheap. sure you can use stock exhaust but you wont see to much of a gain in doing so. I went with a 3"single exhaust with flowmaster and also had the Y pipe reworked to bolt up and payed about 240. Now dont skimp on headers. if you go cheap you will regret it. gibson,jba,edelbrock bassani are all good products. the summit shorties are cheap but the craftsmanship is poor.

later

 

I agree completely with Kemicalburns on the headers. Don't skimp, you will only make things more difficult on yourself.

Answer to question one: Many short header manufaturers design their products to bolt in as a "direct replacement" for the stock manifolds. The one's Kem listed all do as I recall. (one thing to keep in mind when swapping is the bracketry that mounts to the stock exhaust bolts and studs - motor lifting eyes, dipstick tube, support brackets etc. They may not fit as they did and may require some custom bending or longer header bolts with spacers to compensate for the change in thickness from the stock mannifold to the thinner header flange).

Answer to question two: Again, many manufacturers make complete exhaust systems. Some only make "cat-back" systems which will only replace the system from the catalytic converter...BACK! (Guys, correct me if I'm wrong here) AFAIK only Bassani is currently making an aftermarket Y-pipe for these trucks. Its a direct replacement for the stock Y-pipe so it cna be used with or without Bassani's headers in front of it and the factory exhaust behind it.

Answer to question three: NO, not at all. Any time you can get the exhaust gases out of the combustion chambers quicker you are going to improve your performance. When looking at headers, go for equal length headers. They allow the exhaust from the previous cylinder to help draw the next one's down and out more efficiently. Now it is possible to get too much exhaust scavenged away too quickly and that will result in low-end torque loss. Thats a problem for duals that are too big for the engine/vehicle combo. Otherwise, go for the headers, you WILL see and feel the improvement.

 

To touch base with what Kemicalburns and Greystreak said, the header quality is crucial to the quality of the final fit, operation and maintenance
of the headers purchased.

I love JBAs personally, I like their patened firecone design located in their collector. which helps keep the exhaust pressure high and the hot gases moving at a high rate of speed, effectively siphoning (ie:scavenging) the exhaust from the cylinder much better with better consistency.

This is where I will disagree with Kemicalburns, headers will improve the exhaustflow whether or not you have upgraded the rest of the system. How well the headers work depends on how much you adjust the rest of the exhaust to compliment the headers.

In order to purchase the right units, you must ensure you get the thick laser cut flanges, smaller primary tubes (for low end torque) and the shorty config with all the smog fittings.

Another personal prefference is the thermal barrier coating....inside and out of the header....this lower engine bay temps by at least 100 degrees F and improves power output by lower temps of air being taken in....this also helps keep the exhaust gases hotter thus moving them out of the engine with higher efficiency.

GS is right...don't skimp in this area...the better headers require less maintenance....ie:gasket changes, retorquing of bolts or studs etc..