Are they amazing? Or should I go with 1 7/8ths?

How difficult are the set from Kooks to install? (If anyone knows, that is...)

 

wuts your engine setup look like? if you have stock cubes youre not gonna really need 2" primaries

 

Yeah, unless you are fixing to drop several grand into your engine and bump it up into the 500+ HP range really quick, 2" primaries aren't really going to do much. They will flow nicely, but more than likely your intake and heads will become a limiting factor and you won't see the full amount of gains you could with 2".

At stock to lightly modified, a set of 1 3/4 tends to be all you need. If you know you are gonna be pushing over time for around 450, then 1 7/8 would be good.

 

Has anyone done a dyno test on a stock cube motor between 1 7/8ths and 2"?

The only reason I'm wondering is because many said there would be no gain between 1 3/4 and 1 7/8 on stock cubes and that you would lose low-end torque, but we have found these claims to be unsubstantiated.

There's also the issue of spark plugs and installation. Oh, so many questions! But if I'm spending $1500 on headers and a Y, I'm intent on getting all of the answers

 

I bought a set of 2'' headers a while ago from the classifieds for $600 shipped. I am in the process of installing an L92 short block with TFS 225 heads, a ported FAST 90mm intake, 100mm TB, and a solid roller cam. I was originally looking for a 1-7/8ths header, but stumbled upon the 2''s. I did some research and based buying them on:
http://www.camaro5.com/forums/showthread.php?t=63640
Keep in mind that is on an oem LS3 engine, but the results kind of suprised me.

 

nice thread, thanks for sharing.

 

Ive installed 2 sets of Kooks 2" headers and they are in everyway amazing. Plug access is easy, fitment couldnt be better, there is clearence everywhere. Best fitting header I have installed. If you figure most 1 and 7/8 headers that are good cost around the 7-900 range, Kooks 2" are right there so why not spend the extra cash. You can also get y pipes that can be either to a stock catback, 3", 3.5" or 4". Those fit really well also. If your already spending the money get the 2"

 

Here is the reason on why to use the 1-7/8's over the 2". This is from the link that was provided above..

A few Reasons, the additional cost does not justify the gains.
They are a Tighter fit.
They are Heavier
Most manufacturers offer a 1 7/8 headers so they are easier to get.
The biggest gains from headers are in the middle of the curve where you drive most and you can't tell the difference between 1 7/8 and 2 inch, on the dyno graph or in the car.

Unless your Racing you won't miss the 5 HP at 6300 RPM, your not there enough to use it on the street.

I have Kooks 1-7/8 headers and I love them. Great fitment and good floor clearance.
I also have some for sale if interested.

 

Heavier? this point is mute because the same argument can be said for going from 1 3/4 to 1 7/8..

5 HP is 5 HP....People spend stupid money to gain 5 HP. Take for example an underdrive pulley or swap out an h-pipe for an x-pipe or even a new style air lid...list goes on.

If you can get 2" headers for nearly the same cost or within couple hundred dollars? why not? Significant difference in price....probably not.

 

I do plan on replacing the rod bolts (yay stretch gauges) and springs so I may safely increase the red line and shift points to 6500rpm.

The difference between either 1 3/4" or 1 7/8" and 2" is one Ulysses S. Grant. $10/hp is a pretty good price.

The only things I would be worried about at this point would be the fit. I'll be putting on solid motor mounts at the same time, so hopefully there won't be any clearance issues.

I was considering another manufacturer, but after reading about their horrible customer service I've decided to go with the more expensive stainless manufacturer. Any word on Kook's CS department?

 

Ive never had an issue with getting ahold of Kooks CS.

As for weight on the 2" could not believe they were that light, I felt like I was gonna break the damn things, compared to a set of american racing 1 7/8s I just installed they were at least half the weight and fit 20x better.

 

^ The first time I picked them up I was suprised at how light my 2'' kooks were. They're way lighter than stock manifolds.