Header Length:

GM A-Body Vehicles for Systems with Balance
Tube / H-Pipe. Occasionally with Long Tube Headers, we'll come up with a situation where the total length of the system including mufflers comes up short.  This will happen rarely, but when it does it will be with a combination of short muffler (like say 13" case) and a header that is unusually short.
The only vehicles we've run into this so far is Pontiac for some reason.  To check, if the distance from the end of the header to the center of the axle is more than 68" + muffler case length, then an extension will be needed.  Remember, for example if you need 14" more, you will need an extension that is longer than 14" since you will lose about 2" of overlap as the extension slip-fits over the piece it is being attached to.  Play it safe and get the 22" ones.  EXT25022X or EXT30022X.  Don't forget clamps unless you intend to weld.

Notes Page
Typical Block Hugger
Has Ball & Socket Coll. with 2-Bolt Flange - some have 3-Bolt Flange.
Typical Shorty Header - this one has Slip-On Collectors, so either a Slip-On Reducer or a Ball & Socket Reducer will be needed.
Longer than Block Hugger above.  Block Hugger or Shorty?  Either way, we have to get 'down' under the floor pan, then aim back.
Shorty & Block Hugger Headers:
We define Shorty Headers as those which actually come down under the vehicle like Long Tube Headers, but end very quickly at the front half of the transmission.  Block Huggers we think of as actually ending BEFORE getting down under the floor pan (sorta more like a exhaust manifold).
  • Shorty Headers will require an extension to reach back to meet the system.  How long an extension?  Use this to determine: if the distance from the end of the header to the center of the axle is more than 68" + muffler case length, then an extension will be needed.  Remember, for example if you need 14" more, you will need an extension that is longer than 14" since you will lose about 2" of overlap as the extension slip-fits over the piece it is being attached to.  Play it safe and get the 22" ones.  EXT25022X or EXT30022X.  Don't forget clamps unless you intend to weld.
  • Block Hugger Headers present a different situation.  To reach back to the system you will need basically a downpipe.  This will have to be made.  We have what we call Make-a-Downpipe Kits (MaD Kits).  The one you need depends on the end of the Block Huggers you have. 
                     If they have the traditional 3-Bolt Collector flange, then you would need those classified as Kit 2.
                     If they have something that looks more than what is typically found on a stock exhaust manifold, then Kit 1.
                     If they have neither of the above, then you will need a Kit 3 and probably use Ball & Socket Reducers. 

If you know of any additions or exceptions to any of the notes below, please email us so we can update the note.  Thanks and Blessings!   Email Here....
Going Fast is Our Business.
1st Gen Muffler Exception:
The 16" Super Turbo Muffler will fit with some minor triming off the rear snout of the muffler and/or some minor triming off the front of the tailpipe as it goes into the muffler.

The 17" Flowmaster 50 series mufflers will fit also, BUT will most likely require cutting off most of the rear snout of the muffler and maybe some of the front of the tailpipe, then welding it together.