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JBA Header Fitment

Johnny M

Active Member
So tonight i decided to do a full test fit of my headers and i was pretty confused at how bad the fitment was.

There's four bolts holes on the headers around each exhaust port however the most i will get without drilling new holes is two per port. Top and bottom, is that enough?

On the Headers I will have to slightly modify 5-7 of the holes on each side. take about 2-4mm off one edge of the hole to get the bolt hole to line up with the heads.

I have a 428 with stock heads and JBA full length Headers.

Is this normal or could i have the wrong headers or different type of bolt pattern on the heads?

Thanks,

Johnny
 
What header part number and cylinder heads?
Are they 1650

Im curious becasue these fit great with our AFR heads but not too good with edelbrock or brodix
 
Thanks for the insight Jason. I just had a look at the part numbers on the headers and the heads

I bought the JBA Tri-Y Headers for ‘67 - ‘70 Mustang Big Blocks :: Part# 6656. However, just checked out the JBA website and it tells me this about my headers
JBA p/n 6656S headers are designed to fit the 67-70 390 GT Mustang equipped with a 390 GT 14 bolt cylinder head and factory transmissions.

If my reckoning is right I should in fact have the part# 6654

JBA p/n 6654S headers are designed to fit ‘67 - ‘70 390/427/428/428CJ Mustangs equipped with a 5 spd manual transmission and hydraulic or cable clutch. (High Rise, Med Rise, Low Rise, CJ and Tunnel Port)

So if this is causing the issue then Summit sent me the wrong part. :rp

And since i ordered the part over two years ago there is no way i have any come back. Thats a serious fu$k up for a $1,100 part.
 
And since i ordered the part over two years ago there is no way i have any come back. Thats a serious fu$k up for a $1,100 part.

I'd call Summit and explain the situation/delay. I've had them work with me in the past and their customer service is usually pretty reasonable.
 
"daveSanborn" said:
I'd call Summit and explain the situation/delay. I've had them work with me in the past and their customer service is usually pretty reasonable.

I'll give them a call monday, I've always dealt with the same guy over there so he knows me and my build and they might do something for me.

But without the original packaging and some minor skuffs and overspray i doubt they will take them back.

As you say its worth a shot.......maybe they will do something for my next order. I've spents $1,000s with them over the last 3 years.
 
i'm confused. are you trying to put in four bolts per port? aren't the extra holes simply for different bolt pattern headers/heads?
 
"buckeyedemon" said:
i'm confused. are you trying to put in four bolts per port? aren't the extra holes simply for different bolt pattern headers/heads?

No, this is just to get two bolts per port. only 2-3 holes per side currently line up.
 
Re: JBA Header Fitment - Wrong Headers

I did a little more homework on this one and it looks like a total cluster fu$k......

I called JBA tech support and it turns out that I do in fact have the wrong headers. :puk They said I could try checking to see if the ports will line up and try drilling new holes where necessary but that is something I really do not want to do. The items I have are specific only to 390 cylinder heads(Part# 6656SJS) despite most 390/428 parts being interchangeable.

So i called Summit and the best they can do is offer me a 15% discount on the new set. (Part# 6654SJS) I will try to sell them over here but 390 motors are rare and someone wanting to spend big money on ceramic coated headers is even rarer.

I might just take a look to see if it is possible to alter the ones I have. Is there any trick to check if the ports lines up. I was thinking about using some tracing paper and making a impression of the cylinder head ports and then another of the ports on the JBA headers then use the 2-3 holes that line you as reference points. any others ideas?


And, If you know anyone looking for a cheap set of unused JBA ceramic coated headers for a 390 motor then please let me know....I will take a hit and even pay shipping to the USA (east coast). And I'm some of the guys on here will even vouch for me despite being "Johnny Foreigner".

Any ideas, suggestions, help, sympathy, money, free beer or swimwear models will be greatly appreciated. :shrug
 
Re: JBA Header Fitment - Wrong Headers

"Johnny M" said:
I might just take a look to see if it is possible to alter the ones I have. Is there any trick to check if the ports lines up. I was thinking about using some tracing paper and making a impression of the cylinder head ports and then another of the ports on the JBA headers then use the 2-3 holes that line you as reference points. any others ideas?

First off... is the flange the only problem? If there are other interference issue I probably wouldn't bother to rework them.

Check with JBA to see if there is a specific one piece gasket that could be used as a template to verify the placement of the ports and mounting holes. If not, would they be willing to supply you with a mechanical drawing that you could use as refernce to rework the flange?

Who was it that recently had acquired a set of Sanderson headers and found out they were wrong for their application... Sanderson stepped up bigtime and offered to do a direct swap... Perhaps JBA will step up and offer you some help here too.
 
Johnny,

Did you order the wrong headers (for the 390 motor).... or did Summit in error send you the 390 headers when you had correctly ordered the 428 headers?

If you ordered the correct headers and Summit in error sent you the 390 headers instead, I wouldn't let this go until Summit made this right. Maybe you need to talk to a supervisor at Summit? Have them pull up your sales history and don't take no for an answer.
 
Dave
That is the problem. I verbally ordered the Headers so i have no written record of exactly what i ordered. As far as I remember I asked for a set of Ceramic coated headers for a 428 motor and I did not specify any JBA part number. They sent me the 390GT headers and no doubt the Summit sales agent thought the parts were interchangeable like most 390/428 parts. Normally i would dig my heels in on a $1200 part but i bought them over 2 years ago and I should have checked the part before now. Do you still think i have a chance in this circumstance?

I've prob spent $8k with them in the last 2-3 years and have another $500 order i am about to pull the trigger on.
 
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