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Which header brands have actual 2.5" exhaust opening?
Posted: September 6th, 2020, 10:42 am
by 1984Laredo
While compiling my parts list, I've come across something that apparently varies greatly among aftermarket headers. What header manufacturers out there sell a header that has a true 2.5" diameter opening at the collector flange? Some list specs that show it as 2.125", others list no specs at all. And others, such as Gibson (which I was really leaning towards until my interaction with their "tech" guy), could not even tell me what their size was. I had email and phone communications with their tech support, and all he could tell me was "it replaces OEM"...
It looks like Doug Thorley is a 2.5" outlet.
I'm not sure about Banks. I've read conflicting info on them. Does anyone have a definitive answer?
Gibson is out.
Any other reputable ones that are 2.5"?
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 8:21 am
by 275/350 I-6
I have a Banks Revolver Installed on my engine, that I just put in my CJ-7. When I got it, I measured it at 2.5”, and ordered tubing, muffler & a cat, plus some flanges to make the system removable for maintenance, it’s all 2.5”. After seeing your question, I looked into the size a little closer just be be sure.
The header & engine are installed, but the fenders & radiator/ grill are not, so I can still get in there pretty easy. I stuck a tape measure in there, but it’s hard to get it exactly where I want it, but is appears the widest diameter at the flange is 2.5”, but just a short distance in, it appears to drop down to something closer to maybe 2.25”.
The exhaust pipe I bought for the system is 2.5” OD. I believe it is safe to say the Banks Revolver has a 2 bolt collector flange with a 2.5” diameter.
This picture is the collector flange at the end of the header.
FC3FB6FF-38C8-41EA-B830-95C23C1B25FD.jpeg
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 8:23 am
by 275/350 I-6
This picture is the 2 bolt flange I bought for the system.
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 8:24 am
by 275/350 I-6
This is the same flange bolted to the header.
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 8:27 am
by 275/350 I-6
This picture is the same flange sitting on a small pieces of the 2.5” OD exhaust pipe, I welded them together for practice.
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 8:37 am
by 275/350 I-6
FYI...I am not going to use the flange in the pictures. The header comes with a donut to seal the header to the OEM down pipe. The down pipe has a small ring built into it that centers the donut, so it seals up with no leaks. I’m going to acquire a used pipe and cut the end of it off to use, so the donut is held in place. I will weld my pipe to the used flange that I’m going to cut off of the used down pipe.
I’ll post more pictures after I get the pipe, and I cut the end off of it.
One more thing, the Banks header is expensive, but it is well built and appears to be very hi quality. I don’t think it’s doing to crack like the others crack, but time will tell, concerning cracking.
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 8:47 am
by 275/350 I-6
One more picture of the Banks Revolver header installed on the engine.
9D5D178D-5007-4DC9-BE78-6DE9FCAEA74A.jpeg
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 5:09 pm
by 1984Laredo
Thanks so much for measuring that and posting the pictures.
Btw, exactly which AMC Blue is that? I’m leaning towards that color on mine, especially since it’ll be going into a CJ7. I’ve seen a lot of different shades and variations of AMC Blue, but I think I like yours the best. Where’d you get it?
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 10th, 2020, 5:23 pm
by 275/350 I-6
I bought it online from Amazon.
Re: Which header brands have actual 2.5" exhaust opening?
Posted: September 11th, 2020, 5:20 am
by 275/350 I-6
This paint looks nice in a well lite area. I know my 1985 CJ-7 came with a black engine. I had a 1986 CJ-7 new off the dealer lot, and it has a black engine to. I’ve had many earlier AMC cars that had blue engines, so I decided to put a blue engine in my AMC.
I put the engine/TF999/Dana 300 in as an assembly last weekend.
Re: Which header brands have actual 2.5" exhaust opening?
Posted: December 15th, 2022, 5:18 pm
by Cam Hensley
275/350 I-6 wrote: ↑September 10th, 2020, 8:21 am
I have a Banks Revolver Installed on my engine, that I just put in my CJ-7. When I got it, I measured it at 2.5”, and ordered tubing, muffler & a cat, plus some flanges to make the system removable for maintenance, it’s all 2.5”. After seeing your question, I looked into the size a little closer just be be sure.
The header & engine are installed, but the fenders & radiator/ grill are not, so I can still get in there pretty easy. I stuck a tape measure in there, but it’s hard to get it exactly where I want it, but is appears the widest diameter at the flange is 2.5”, but just a short distance in, it appears to drop down to something closer to maybe 2.25”.
The exhaust pipe I bought for the system is 2.5” OD. I believe it is safe to say the Banks Revolver has a 2 bolt collector flange with a 2.5” diameter.
This picture is the collector flange at the end of the header.
FC3FB6FF-38C8-41EA-B830-95C23C1B25FD.jpeg
Do you remember where you got the 2.5" tubing from? Was it already fabbed for your jeep or just straight stock material that needed to be fit.