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Mac 351w longtube headers hit floor board

6319 Views 32 Replies 7 Participants Last post by  408foureye
I mocked up my drivetrain and found the pass side collector hitting the floor board. Driver side looks fine. When I measure the collector height from the ground, the pass side sits up 1" higher, which is causing the floor board interference. The headers are 1 3/4 Mac longtubes on a 351w with convertible mounts. I also bolted up the headers with the engine block and heads on the stand - the collectors are still uneven by the same amount. Anyone else have this issue?
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I feel for you man. I hope you have better luck with those than I did mine. I ordered some direct from Jet-Hot to fit a 302 five speed, really expensive with the ceramic coated black. They did not fit well; Rubbed the passenger side on the K-member. Would not bolt up to Mac's Prochamber with a Tremec 3550 due to the different exhaust hanger I think. Regardless, terrible fit.

Jet-Hot didn't want anything to do with it since they didn't make them. Mac wanted me to send them back; they wouldn't send me a call tag, I had to pay to have them sent back to be checked on the jig. Then they sent them back and said they fit on the jig fine so it was not their problem. After their sub-par customer service, Mac will NEVER get any more of my money. They are just collecting dust now along with the matching Prochamber.

Good luck to you.
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Wanna sell them?
Actually, yes. I'll have to dig up my receipt, paperwork and all.
Can you do me a favor and post a picture of the passenger side header? I would like to compare it to mine.
I'll get you a pic later today along with a height measurement from flange to collector.
Can you do me a favor and post a picture of the passenger side header? I would like to compare it to mine.
Here is the pic. I get about 12 1/4 inches drop from the flange to the top of the collector (meaning the 2 bolt flange). Hope this helps.

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TF 2016. Just a thought here, would it help if the collector flange was turned 90* and then reattached? I would figure the flange is what you're having the clearance problem with due to that being the highest point there. How much drop do you measure?
Hmmm... my pass side one looks totally different! What part number are those?

This is what mine looks like -
Did you get a drop measurement? Are yours 1 3/4? Mine are 1 5/8 which may make for different routing of the primaries than yours.
No problem, glad to help out. Especially when it comes to someone having trouble with Mac.
Update -

It's been over a month since I sent back the headers and I haven't heard anything from them. I emailed and left phone messages. Now I'm pi$$ed.

These guys are total flakes to deal with. I had to wait over 2 weeks just for a call tag. Now over a month after they received them, I'm $350 out of pocket and don't even have scrap metal to show for it. WTF... this sucks!

MAC will never get another dime of my business and I'll make sure other people will be sufficiently warned.
This is pretty much the same experience I had with them. I went to BBB and did a terrible review and they tried to defend themselves with the same BS they said to me in correspondence. Hope it works out better than mine did. Good luck.
That's sad to hear. At least they were talking to you.

If they don't end up making good on this, I will pay them a visit and also talk to the local police. I bought my headers directly from them and I'm in the warranty period, so they are fully obligated to make good on this.
Yeah, they were talking to me defending their poor quality control methods and how they weren't going to take care of their customer. But I definitely feel for you man; as I've said before, mine are just collecting dust along with a nice UNUSED Prochamber. Hope you get some resolution.
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