5 inch ???

Grand Rock,
I have been researching exhaust for my 06 Ram. I first had to have stacks even if my wife calls me a redneck, as if that was bad. I found the Grand Rock product and it is exactly what I am looking for. Now I have a couple of application questions.

I have the stock exhaust and will stick with a cat back system, as I live in California and the Enviro-Nazis will come calling if take out the cat. My question is, do you have a short 4" to 5" adapter to put on the back of the cat so I can use 5" from there back and up?

Second question, how hot does the exhaust get in the bed? I haul hay in the truck and need to know what I will have to do to prevent a miss-hap.:ft: Not the fire I'd like to see!

Lastly, how far above the cab does the standard 36" stacks extend?

Thanks alot.

the exhaust can get hot enough to melt plastic couple of my buddies have done it. as for the 4" to 5" adapter i know they make them.as for the stack since the stack fits down into the cross pipe you can cut the stack to is what ever height you want. i'll pm you josh's number at grand rock

I need it a little above the cab for my horse trailer.

Thank you, and great name.

you can talk to josh and he will know which height would be best

Everything Leonard told ya is pretty much true! We do make the adapters to go 4" up to 5". How ever, with our truck already sportin' the 4" exhaust on it, you really do not need this adapter. Our standard universal system will tie into any 4" exhaust under the truck. How ever if you with to go 5" as soon as possible, we can do that to for ya.

You have to cut an obblong hole in the truck bed to allow the y-pipe to rest securly on the saddle clamps that sit on the bed floor...



these saddle clamps get bolted down, and secures the y-pipe, and provides a great solid mount for the stacks. Under the bed there is a 90* elbow, and a piece of flex that connects it to the rest of the exhaust under the truck. Since you haul hay in the back of the truck, I suggest getting some sort of box cover for the y-pipe. We don't offer a box, but we do offer a gaurd of some sort.



I believe the box is the better way to go for your application and use of your truck.

The 36" bull horn would be a good 1-2 inches above the cab. I would suggest going with a 48". This will give you enough stack to trim to the look you're looking for.

I hope this helps..if you have more questions, feel free to contact me!

Nice setup Josh! How long does it take to install?

NADM Marketing said:

Nice setup Josh! How long does it take to install?

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:thankyou2:

Installation time depends on if you have all the proper tools, or how handy you are with cutting tools. This particular installation we used a 5.5" hole saw to start, then finished up with a scroll saw. All in all it will probably take 2-4 hours. Just remember to double and triple check your measurments before cutting...

i like those kinda stacks looks good

Texaschromeboy said:

i like those kinda stacks looks good

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:thankyou2:

Those would be the 6" Aussie stacks, 36" overall length.

i prefer aussie over bullhaulers but on a semi they both look good

Thanks Josh, those aussies look great.
Am I understanding correctly? A stack is straight all the way to the bottom so I can cut a 48" to any shorter length.
I was thinking of the same solution for the hay, I can fab a box around the exhaust in the bed. Do you think the stacks would be cool enough above the bed? I see your bed liner has not melted, how long have the stacks been installed?
My thinking on going to 5" right away is to accomodate the rest of the system change at a later date. I am hoping someone will come up with a 5" high flow cat, fat chance but hoing.

diesel4play said:

Thanks Josh, those aussies look great.
Am I understanding correctly? A stack is straight all the way to the bottom so I can cut a 48" to any shorter length.
I was thinking of the same solution for the hay, I can fab a box around the exhaust in the bed. Do you think the stacks would be cool enough above the bed? I see your bed liner has not melted, how long have the stacks been installed?
My thinking on going to 5" right away is to accomodate the rest of the system change at a later date. I am hoping someone will come up with a 5" high flow cat, fat chance but hoing.

Click to expand...

Not a problem. 4" and 5" stacks are straight...the 6" (like the Aussie's pictured) and the 7" stacks are reduced to 5" O.D. bottom. So the room to trim a 6 or 7 inch stack is very minimal. As for how cool the stacks are, that depends on the rest of your mod's. Keeping your cat like you are will give you a higher EGT than running without one. But being in Cali...you don't have much of a choice there do ya. That is not my truck bang wish it was though, I don't own a truck at this moment) but no he did not have an issue that I'm aware of with the spray in bed liner. That stuff was in there pretty thick too....I've even seen some with the drop in bed liners not having a issue either. Going with 5" as soon as possible, will help keep the heat down as well.

I have had stacks in my truck for about a year and a half now, and my old truck had them for about 2 years and I have never had any problem with the bed liner bubbling or peeling or melting, as long as you keep a torch away from it you should be fine.