For applications that we do not have listed, it is often possible to take a true dual header system (less collector reducers, since you won't be needing them!) and have made a downpipe to come from the manifold down to our system. Sometimes you can get a reputable muffler shop to do this for you, or if you are talented in this area, you may be able to cut and weld together mandrel bent elbows in such a way to make your own downpipe. Also, you might be able to use one of our Make-A-Downpipe Kits to make your own downpipe.  We can give you some ideas in this area if you would like.

Manifold Systems come with Downpipes, Headpipes, Balance Tube (or X-Pipe) and Tailpipes along with all appropriate mounting hardware.

Header Systems all come with Collector Reducers, Headpipes, Balance Tube and Tailpipes along with the appropriate mounting hardware. Some of these systems utilize a two-piece headpipe (GM G-Body) and some utilize a two-piece tailpipe (GM F-Body and some GM A-Body).

The Headpipes (forward of the muffler) are made longer than generally necessary (43" for most GM applications & 39" for Mopar applications) to cover most situations. This depends on header and muffler length. The end of the header collector normally should come within 3" to 4" of the tranny crossmember. If not, there is a possibility the headpipe may not reach far enough forward to the header.

We have purposely constructed our Collector Reducer 14" to help with this potential problem. If you have too much pipe between the header and mufflers, just cut off with you don't need (either from the headpipe or the collector reducer OR both).

Being selective where you cut and how much, can help you locate the bends of the headpipe so it will tuck up close to the contours of the underbody of the vehicle. This helps with ground clearance and appearance.

Our collector reducer and headpipe combined length before cutting is 55" for GM applications and 53" for Mopar. If more length is needed, then you will need one of the Extension Kits or on GM applications, the HL Series Headpipes!

Determining if you need this extension kit before ordering can save some time and aggravation. As far as we know, all Big Block header applications are long enough and present no problems unless you have a longer wheelbase vehicle. Please note that Pontiac A-Body headers tend to be shorter than others, which increases the probability of coming up short. This occasionally happens with some Chevelle headers, but is rare. We generally recommend that the Pontiac guys go with the HL Headpipes to begin with. Our headpipes will not reach "shorty" headers or stock exhaust manifolds. Your only option is to purchase our system (minus collector reducers in some instances) and have a reputable shop make the piece from the system up to the "shorty" headers or stock manifolds. This is frequently done, however, and it is easier to do with the 2.5" system.

Another installation variation which sometimes occurs, is that one of the headers will be tucked up tighter toward the transmission, thus exiting closer to the center of the vehicle than normal. This often causes the headpipe to actually hit the drive shaft. We have a "SPLIT" Headpipe which can help. Since the amount being "tucked in" can vary, we don't have any way of making Headpipes to cover these rare variations. This "SPLIT" Headpipe actually makes adapting easier and cleaner.

Collector Reducers -- Our Performance collector reducers are provided with all Header Systems. they are part of the Kit.; They have the standard 3-bolt mounting flange. We will need to know the collector size of your headers. This usually either 3" or 3.5". Headers with 3.5" collectors usually have 2" or bigger primary tubes (in other words for well "built" big engines), and headers with 3" collectors have 1 7/8" or smaller primaries. However, there are several header applications that have 1 7/8" primaries along with 3.5" collectors. Occasionally, we will find a header with 2.5" collectors. We do have reducers (2.5" x 2.5") for these headers. You will have to use a 2.5" system or do some relatively simple adapting if you just want a 3" system with 2.5" collectors. We can help with this adapting although there will be no performance advantage to doing so.

Collector Size can be determined two basic ways. One is to measure the inside diameter of the exit opening of the header and the other more exact way is to measure the distance between any two bolt holes (center to center of each). If you get a measurement of just under 4", then you have 3.5" collectors. If you get a measurement of just under 3.5", then you have 3" collectors. If you get something even smaller, then you have 2.5" collectors.

Balance Tubes (Crossovers) -- All of our True dual systems come with a Balance Tube. The purpose is to help equalize the pulses between the left and right side of the system. As a side benefit, especially on 2.5" systems, loudness is reduced. We do not pre-install them on the headpipes because often this make installation more difficult. They are what we call, a "cut and weld" installation. This is about the only thing in our system installation that requires welding!

X-Pipe Kits -- These kits include all necessary to reach from either the Downpipe (for Manifold applications) or Header back to the mufflers.  They come with or without clamps depending on if you feel you need them.  The X-Junction (which can be purchased separate by itself) is generally placed immediately after the forward universal joint.  Placing it further back may cause interference with the up/down movement of the driveshaft.

Tailpipes -- Generally speaking, we do try to design our tailpipes to exit in the stock location. However, for example, the GM A-Body vehicles varied a lot with exit location over the years, so we have not gotten into making all the different variations. There are typically two main variations with the GM G-Body and we have done those. On the GM F-Body vehicles we have just one design, but it can be cut behind the wheel for behind the wheel exit. The Mopar vehicles were all pretty consistent, so we have them covered fairly well

Our profiles allow for typical suspension upgrades and modifications and allow for wide tire installation. All tailpipe design to date utilizes mufflers with offset outlets and inlets. The GM G-Body and all Mopar installations require the mufflers to be "angled" about 10 degrees relative to the center of the vehicle.

      "All performance exhaust products for pollution controlled vehicles are intended for off-road or drag strip use only"

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This page last updated:  10/17/2011