Custom Header Questions....
Thread Starter
On The Tree
iTrader: (2)
Joined: Dec 2005
Posts: 167
Likes: 3
From: Key Largo Florida
Custom Header Questions.... Hey Guys,,,
Well it looks like the header project is about to start and I have a couple of quick questions.
First, The what is the hole size (tubing size) on the GM Exahust Flange, part number 12480130?? I'd like to use 1 5/8 tube.
Second,, how are you cutting the tubes?? I have a abrasive chop saw,,, but it's a bit of a pain. I looked into band saw but space in the garage is an issue. Read about autozone exahust tube cutter. WHat's the trick setup for nice stright cuts???
Lastly,,,, what gauge tube are you using,, 18 or 16??
Thanks!
Well it looks like the header project is about to start and I have a couple of quick questions.
First, The what is the hole size (tubing size) on the GM Exahust Flange, part number 12480130?? I'd like to use 1 5/8 tube.
Second,, how are you cutting the tubes?? I have a abrasive chop saw,,, but it's a bit of a pain. I looked into band saw but space in the garage is an issue. Read about autozone exahust tube cutter. WHat's the trick setup for nice stright cuts???
Lastly,,,, what gauge tube are you using,, 18 or 16??
Thanks!
The GM flanges have 1 5/8" outlets. A band saw would certinaly make cuts easier, but you should be fine with a chop saw. Just take your time and make sure you don't lose any fingies or tosies 
BTW, someone posted a link to this place in another forum and they sell mandrel bends dirt cheap.
http://store.racing-solutions.org/hebukit1.html
BTW, someone posted a link to this place in another forum and they sell mandrel bends dirt cheap.
http://store.racing-solutions.org/hebukit1.html
I've only seen the 1 5/8" flange from GM, but you could probably call them and ask. I think I've seen 1 3/4" flanges around from Burns or Hooker or something, but they were pretty pricey.
On The Tree
Joined: Jul 2004
Posts: 166
Likes: 0
From: Stockholm, Sweden
I would say that the GM #12480130 is suitable for both 1 3/4 and 1 5/8.
The holes in the flange will let you stick the 1 3/4 tube in the hole and weld it on the "inside"
The 1 5/8s will match the hole but you have to weld on the "outside".
As for cutting I used a plain hacksaw, just be careful and you can cut it straght. I mark the tube all the way for the cut and then follow it with the saw. Important to have fresh blades.
Bandsaw would be the best but for one job it would be overkill to buy one.
Jan
The holes in the flange will let you stick the 1 3/4 tube in the hole and weld it on the "inside"
The 1 5/8s will match the hole but you have to weld on the "outside".
As for cutting I used a plain hacksaw, just be careful and you can cut it straght. I mark the tube all the way for the cut and then follow it with the saw. Important to have fresh blades.
Bandsaw would be the best but for one job it would be overkill to buy one.
Jan
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TECH Apprentice
Joined: Aug 2005
Posts: 347
Likes: 0
From: Dover Arkansas
Huh? The 13/4 flange, the 13/4 header tube fit right in the hole. 15/8 is a smaller tube, won't even touch the sides of the flange hole. You might be able to get it roled to spread the tube out at the end to match the end of the tube to the inside of the 13/4 hole, kind of a step in the tube diameter.
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Verdad Gallardo TECH Apprentice
Joined: Aug 2005
Posts: 347
Likes: 0
From: Dover Arkansas
The above mentioned part #12480130, at http://www.gmgoodwrench.com. This is what I have. The hole on the flanges I recieved were 13/4".
If you don't have a bandsaw, the next best thing I have used is a 4 inch cut-off wheel on a right angle grinder. Works well. Also helps if you put tape around the tube for a guide.
