For those who have the right tools, this kit will allow you to make your own downpipe to come off exhaust manifolds. The manifolds will have to be coming down close to 45º or close to 90º for this to work. 

Instructional Diagram

Basically what you do is take the 2½" Elbow and trim the height so when it is attached to the bottom of the manifold, it won't be too low for ground clearance, then take it to a muffler shop to have them flare out the top to mate to the bottom of your manifold. IF the angle you are dealing with is not exactly 45º or 90º, then you will have to "cut out" a sliver or pie shaped piece in the bend to make the bend either a little bit more or a little bit less than what it is. Once you have this new correct angle determined, then you will need to weld it together. This step usually takes someone who knows what they are doing to make the right cuts, etc., but it can be done. However, it doesn't work very well if you have to make very much of an adjustment in the size of the angle. You will need to have a muffler shop "flare out" the top end of the elbow so it will mount to the end of the manifold.  NOTE: It would be a good idea to slip the mounting flange supplied with the kit onto the elbow, before having the top end "flared" welding up the cut in the bend.

Once all this is settled, then you take the Straight Piece of pipe supplied, slip it onto the end of the Elbow, and cut it to the desired length to reach our system headpipes.

In most cases this will work even on 2.25" manifold exits.  Another idea, if you have 2.25" exit openings is to use the piece and mounting flange that you currently have hooking up to the manifold.  Use only approximately the first 3".  Cut off the rest and dispose of.  You can determine how high the elbow should be for adequate ground clearance and slip the 2½" elbow we supply over the bottom end of your hookup to the manifold and weld them together.  If you think you want to do this with the smaller manifold exit opening, then order (GMXSH250102).  It will be the same as the regular kit except will not have the formed flanges.

Each kit comes with (2) formed mounting flanges for mounting to the manifold, (2) Elbows (your choice of 45º or 90º), (2) Straight Pieces of Pipe 22" long expanded on one end and (2) 2½" U-Bolt Clamps.  See Instruction drawings.

          "MAKE A DOWNPIPE" KIT 2 (w/ Manifold Hookups)

Basically, this kit is the same as Kit 1 above except we have added a Manifold Hookup that will bolt directly to the manifold assuming you have the typical "ball type" end on your manifold that will accept a flared pipe.  We have 2 variations of this kit available.  One is for 2½" exit openings on the manifold and the other is for 2.25" exit openings.  If you have 2" openings, then the 2.25 kit probably will work.  The elbows we supply will be 2½".  If you are using the 2.25" Manifold Hookup, then the bottom of it will slip into the top of the elbow and you will weld it together. 

We will need to know if you will need 45º or 90º elbows or one of each.  We will also need to know if you will need 2 or 3-bolt mounting flanges so we can provide the correct flanges.

Basically what you do is take the 2½" Elbow and trim the height so when it is attached to the manifold hookup, it won't be too low for ground clearance, then insert it into the hookup double checking elbow height from the ground.  

Instructional Diagram    <--------   With the Manifold Hookups, attach them to manifold, then follow these instructions.

IF the angle you are dealing with is not exactly 45º or 90º, then you will have to "cut out" a sliver or pie shaped piece in the bend to make the bend either a little bit more or a little bit less than what it is. Once you have this new correct angle determined, then you will need to weld it together. This step usually takes someone who knows what they are doing to make the right cuts, etc., but it can be done. However, it doesn't work very well if you have to make very much of an adjustment in the size of the angle. 

NOTE:  You will need to weld the elbow to the adaptor to insure no leaks.  We highly recommend welding the extension to the elbow also.

NOTE:  The Manifold Hookups will not work or seal if the exit openings on your manifold are 2" or smaller.  The opening needs to be 2.25" to 2½".

NOTE:  There will be cases where you will not have enough room to use the Manifold Hookup as it in itself is 3" long.  Some manifolds come down so low that when using this Manifold Hookup, it places the bend (on 90º elbows) lower than the bottom edge of the vehicle.  You will have to decide if this is acceptable.  If this turns out to be the case, then do not use the Hookup, cut the 90º elbow to the desired height and take the elbow to a muffler shop to have them place a standard 30º flare on it.  You may return the unused Hookup for a refund if you like.

Once all this is settled, then take the Straight Piece of pipe supplied, slip it onto the end of the Elbow, and cut it to the desired length to reach our system headpipes or X-Pipe Forward Extension.  (Note: With the X-Pipe, after all trimming to fit is done, either the front of the Forward Extension or the End of the 22" Extension will need to be expanded for a "slip-fitting" together)

Each kit comes with (2) Manifold Hookups, either 2½" or 2.25", (2)  2½" Elbows (your choice of 45 or 90 Degree), (2) Straight Pieces of Pipe 22" long expanded on one end and (2) 2½" U-Bolt Clamps.

 "MAKE A DOWNPIPE" KIT 3    (for Shorty or Block Hugger Headers)

This kit is the same as Kit 1 above, except Header Collector Flanges are used.  This kit is for Block Hugger type headers with 3" collectors that exit before they come down under the vehicle.  See photo for Kit 1.  These type headers usually always have 3" collectors.  If yours has 3½" collectors, then some adapting may have to be done.  Give us a call and describe your situation, maybe we can help.  If you have 2½" collectors, then use Kit 1 and purchase (2) 2½" collector flanges to weld onto the top of the Elbows.

Also, see the instructional diagram.

Each kit comes with (2) 3" Elbows (your choice of 45 ºor 90º), (2) 3" Collector Flanges to weld onto the top of the Elbow,  (2)   3" Straight Pieces of Pipe 22" long to reach from the elbow back to the Headpipes and (2) 3" U-Bolt Clamps.

These are available to bolt up to 2½" or 2.25" Manifolds.  The 2.25" Hookups will in most cases work with Manifold openings as small as 2" although you might have to "work with" them a little.   In some cases they can be used with a smaller bolt pattern if you elongate inward the holes on the flange and "notch" the flared part a little where the bolt is.  The 2½" Hookups are 3" long with a 1½" to 1.75" expanded end for slipping a 45º or 90º elbow into.  The 2.25" Hookups are 3" long with the bottom end not being expanded.  We highly recommend welding the elbow to the Hookup to prevent exhaust leaks.  2.25" 3-Bolt Flanges; the holes are 2 11/16" apart center to center.

These Manifold Hookups are available with either a 2-Bolt Flange or 3-Bolt Flange.

This idea can be used when the angle is very small such on the Pontiac Long Branch Manifold.  Basically, you are using 2 Straight pieces of pipe and "butt-welding" the ends together.  The bend is not Mandrel Bent, but since the angle is so small, flow is impeded relatively little.  Another possibility exists if you think the angle is approximately 10º, then you might be able to use what we call our 10º adapters.  Pictured in this photo are the 10º adapters (bottom), 19º Tailpipe Turn Down (middle), and 40º Tailpipe turn Down (top).   All three of these items are available in 2½" or 3".