These kits fit ALL Ford, GM, Chevy and Dodge applications, Diesel or Gas. If you have a question about your stack kit, give us a call!

Whether you are heading to the drag strip, tractor pulls, dyno event or just cruising Main Street, YOUR TRUCK NEEDS STACKS!

8 inch Straight, Mitre and Aussie Cut Stacks now available!

Key Features:

• Maximum Exhaust Flow! Pull that hot air away from your engine.

• Increased Fuel Mileage! Smile each time you fill Up!

• Extra Horsepower Gains! Power There When You Absolutely Need It.

• Allows You To Safely Run Extra Horsepower by Reducing EGT’s! All the Performance Without the Hassle.

• Free Shipping on ALL Grand Rock Stack Kits! Save BIG!

• Functional – Route exhaust fumes above and away from livestock, car haulers, and cargo where diesel smoke is unwanted.

Grand Rock introduces their PowerFlow Chrome Dual Stack Kits. A high performance diesel exhaust system with the “Big Rig” look and style for your truck. PowerFlow Dual Stack Kits are a true 4" or 5" diameter from cat to stack exhaust system, with a 4" or 5" diameter hole through the bed required. These chrome kits were designed as a “No Muffler” exhaust system and feature AccuSeal clamps for superior joint sealing. All chrome stacks are 36" in length and feature high quality chrome plating. A 36" stack will get to the top of your truck cab. Longer or shorter stack lengths are available. Chromed rain caps for straight-cut stack tips and stack in-bed diamond-plated or chromed heat shields sold separately.

5, 6, and 7 inch stack tips available in straight, curved, mitre/angle, Aussie, and bull hauler/extended curve cuts for Ford Powerstroke, Dodge Cummins and Chevy/GMC Duramax Trucks and any other truck on the market. 4 inch stack tips are available in straight, curved or mitre/angle cuts. This is a universal kit. Built in the USA. 1 Year Limited Warranty. Have any questions on install? Go to our videos section to see a complete installation.

Why buy the POWERFLOW Exhaust System?

• Precise fit, no need to hammer or adjust anything during installation
• Re-metalized, coated weld area, no premature rust on seams
• All brackets are zinc plated to prevent rust
• AccuSeal clamps join pipes together’ they don’t crush the pipes, making exhaust joints serviceable
• All tubes are de-burred and cleaned; no sharp edges or saw chips

These exhaust stacks are almost constantly on back order with the manufacturer and orders are first come first served with the manufacturer so order yours today and be first in line!

Please note: Your Grand Rock stack kits will be made-to-order, so delivery time for your stacks can vary. 4, 5 and 6 inch kits usually ship within a week or two, while 7 inch kits can sometimes take up to four weeks to ship, but they are usually in stock and will usually ship within a few weeks.

See what our customers have to say about their Grand Rock stacks!

John from Florida
“Hi this is John I just bought exhaust stacks from you guys and I love it, every where I go people look and ask me about it, I like the sound of it. thank you so much I’m sure I will buy stuff for my Dodge truck from you guys in the future. Parleys Diesel Performance is the best! Thanks guys keep up the GREAT Work!”

Richard M. from North Carolina
“Hey guys just wanted to let you know what a lifesaver the stacks I ordered are. The track officials at our local 1/8th mile track were getting sick of me laying smoke down so these stacks have worked perfect to get the smoke up and out of the way. The track officials haven’t bothered me since I put them on, thanks guys.”

Gerald S. from Oklahoma
“I thought I had every accessory known to man on my 6.0L Powerstroke until I saw these! I had to get them, since putting them on I have definitely seen an increase in power and a decrease in EGT’s. You guys ROCK!”

Grand Rock PowerFlow Dual Exhaust Stack Kits will fit:

• All pickup trucks with a standard-width bed.

• Stack Kits work with gas engine trucks. For gas pickups, order 4" stacks (or 5" if you have a Hemi or are running a hot tune). It is critical to maintain sufficient back pressure for your gas engine.

Grand Rock PowerFlow Dual Exhaust Stack Kits will NOT fit:

• If you have a flat bed truck this kit will not fit. You will need to call us to request a parts catalog so you can choose the parts necessary to complete your custom order.

Complete Installation Instructions

NOTE: Before removing the OEM Exhaust System, read all of the instructions and check the contents of this kit against the parts list provided. Please contact us if any pieces are missing. Please check that all ends fit before installing on your truck.

MEASURE TWICE AND CUT ONCE!

1) Remove exhaust from back of cab all the way to the back of truck.

2) Remove the heat shield from the bottom of the bed (if equipped).

3) Measure the inside of the bed, inside bed rail to inside bed rail. This is the total width you will need your kit to be WITH the stacks installed.

4) Figure where you want your kit located. Confirm your hole location from the underside and topside BEFORE drilling any thing.

5) Find a flat surface and slide the long elbow into the y-pipe. Next expose the bottom of the stack, keeping most of the plastic on to protect the chrome. Insert the stacks inside the y-pipe, and measure the width from outside of the stack to the outside of the other. This width should match the width you measured in step 3. If not, you can trim the o.d. end of the long elbow that slides into the y-pipe, giving you the needed measurement.

6) Next measure for your inlet hole template. Start with measuring from the center of the y-pipe to the outside of the stack that would be on the passenger side of the truck. This measurement will be the center point for the template, and should be marked in the bed of the truck. You can now center the template and trace the outline. Now you can cut out the inlet hole for the y-pipe. Please note that depending on where you chose to place the y-pipe you may have a bed cross member that will need to be notched out so the y-pipe will mount correctly to the truck bed.

7) Assemble the y-pipe and long elbow together (trimmed if necessary). Drop the assembly in place, resting on the saddle clamps. These saddle clamps can be placed in the truck bed where you feel will be best for your applications. Remember you need to drill holes for the U-bolts to drop through the bed. Once the saddle clamps are in place, u-bolt holes drilled; bolt the y-pipe assembly down to the truck bed. This SUPPORTS the stacks, and MUST be done for proper installation.

8) With the stacks still in the plastic, uncover the bottom of the stack and install in the y-pipe assembly. Place the “L” bracket in the center of the stack, and mark on the bed rail where the “L” bracket should be mounted. Remove stack, drill hole and mount the “L” bracket. You can flip the “L” brackets to either side to reach the desired look you want.

9) You will now need to slide the AccuSeal clamps on the y-pipe assembly. (starting with the aluminized one then the bright stainless one.) Insert the stack in the y-pipe assembly, and remove the protective sleeve. Next slide the bright stainless clamp up and around BOTH stack and “L” bracket and tighten. Now you can tighten the aluminized clamp at the joint of y-pipe assembly and stack. PLEASE NOTE the “L” brackets are designed for keeping the stacks straight, and not for supporting the weight of stacks or stack kit. If you try to support the weight of the kit and stacks, the “L” brackets CAN and WILL break. Please be sure to follow instructions in step 7.

10) Slip the short 90º elbow into the opening of the Y-pipe (underneath), and clamp using the last AccuSeal clamp. Put the flex over the elbow about 2” to 2 1/2” and then clamp using the wide pre-formed Westfalia clamps.

11) Measure the length from 2 1/2” into the flex forward, to go over your existing pipe that will probably need to be cut, clamp using the last pre-formed Westfalia clamp. If you have 3” or 3 1/2” diameter exhaust, reducers are available.

12) Snug up all clamps, etc. Make sure nothing is bound, rubbing, or touching any thing that it shouldn’t.

13) BEFORE starting engine, make sure the chrome is CLEAN; grease and oil free. A good hand or fingerprints will “BAKE” into the finish if not clean.

14) Tighten everything. Start engine and check for leaks, etc. Retighten accordingly. Take for a test drive and recheck.

15) ENJOY!

Grand Rock has manufactured diesel truck exhaust systems for over 30 years. They custom make 100% of their product in their 53,000 square foot Ohio factory just east of Cleveland. In addition to having OEM Replacement Parts for big rigs like Kenworth, Peterbilt, Mack, Western Star, International, Volvo and Sterling, Grand Rock has created their PowerFlow Division.

The Grand Rock PowerFlow Diesel Pickup stacks bring big rig-style stack kits patterned after traditional tractor-trailer stacks to today’s popular GM Duramax, Ford Powerstroke and Dodge Cummins diesel pickup trucks. They fabricate their 4" and 5” stacks from 16 gauge cold rolled steel, and the 6” and 7” and the brand new 8” stacks are fabricated from 14 gauge cold rolled steel.

After fabrication, most PowerFlow stacks are given a high quality commercial grade durable triple-chrome-plating, although some customers choose to finish the tips themselves and order the stacks without a finish so they can do a custom treatment or coating.

Links

• Manufacturer Product Web Page
• Manufacturer Product Support

Manufacturer Contact Info:

800-321-3674

Grand Rock Truck Exhaust Systems
395 Fountain Avenue
Painesville, OH 44077

Grand Rock Stacks are made to order and are non-returnable.

If you have a question about fitment with your truck, call us before ordering. All sales of Grand Rock product are final.