well stock gt exhaust diameter is 2.25" but it's really beside the point

 

The issue with the BBK and Mac is the inability to drop the Tremec out without removing the passenger side header from the head. I have had the unpleasant task of trying to stab that tranny in a friends Mach and fortunately he had Kooks, because you can get the tranny in and out with those.

I have gone back and forth on this issue myself. paying 2x or 3x the price of a set of Mac's or BBK's seems silly, but I think the big advantage is the ability to get the 3650 in and out without removing the header, and the SS construction...

Dont' forget to budget the $500.00 for a tune no matter which ones you go with...

 

I will need a tune for sure after the install? So its gunna cost me like 1800-2000 to do longtubes... Maybe I will consider installing them myself lol.

 

I was going to do mine to save cost but I decided to have my tuner install them and boy am I glad I did.

 

I just put mine in this weekend. If you plan ahead and make sure you have 2 full days to do it, you can go slow and do a good job. It really wasn't all that bad.

 

I dont know, I would have to ask my dad if he can help me and my uncle has a lift so it might not be too difficult. Im just worried about breaking a header bolt off in the block lol. I am selling my KFX400 so that will fund my exhaust so now im looking at Kooks and ARH. Whats the difference between them and say BBK or MAC besides the conveinence of clearence while dropping the tranny?

 

I have seen a couple ARH kits and a couple Kooks kits installed and I ended up going with ARH for 2 reasons.

1. ARH has better ground clearance
2. ARH is a solid piece so no chance of leaking, where as kooks uses a slip fit and I have seen personally and other people say that have kooks installed, they are prone to leak at the collector.

 

It's not that likely to happen. My advice is to reuse as many of the studs as possible and then use header bolts in the other places. I got close to cross-threading one of the bolts and had to back it out and really lean on it to get it to thread properly. If you take your time and prepare, you won't have much trouble.


The difference is going to be in quality of design and materials. The more expensive stainless materials are going to last longer in rainy, salty climates (be it up north or coastal). I live in Texas and garage the mach so this is not really an issue for me.

As far as fitment goes, I knew the BBK headers had some issues (like that they require a stud or two to be cut down) but that was worth the money saved and was not something I couldn't take a little extra time to take care of. Knowing this ahead of time, the install went perfectly smooth and I'm leak free. Kooks and ARH will not have the design issues that BBK does.

If I have one regret, it is that the BBK hang pretty low. They are going to be an issue when I install coilovers and put the ride height where I want it. I should have gone with MAC since they sit higher but don't cost any more. The reason I didn't is because I had credit at AM and they don't carry MAC anymore. SO I will have to make due. I would recommend MAC as a good compromise between quality and price to anyone in the market that doesn't need stainless material. Otherwise, ARH since I've heard Kooks are a little inadequate for how much they cost.

 

Hey y would u reuse the studs?

 

Less likely to damage the delicate aluminum threads in the block