
Grand Rock introduces their PowerFlow Chrome Single Stack Kits. A high performance diesel exhaust system with the “Big Rig” look and style for your truck. Take a big bold step up in looks and performance with a single exhaust stack kit finished with a triple-chrome plated stack tip from the diesel exhaust experts at Grand Rock Exhaust.
Whether you’re heading to the drag strip, tractor pulls, dyno event or just cruising Main Street, your truck needs a stack kit! These kits fit all Ford, GM, Chevy and Dodge applications, Diesel or Gas. Not just for looks, these stack kits are functional too. Now you can route exhaust fumes above and away from livestock, car haulers, and cargo where diesel smoke is unwanted.
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.
- Precise fit, no need to hammer or adjust anything during installation
- All brackets are zinc plated to prevent rust
- Save Big with Free Shipping on ALL Grand Rock Stack Kits!
- Re-metalized, coated weld area – no premature seam rust
- AccuSeal clamps won’t crush your pipes – , leaving exhaust joints serviceable
- All tubes are de-burred and cleaned; no sharp edges or saw chips

This PowerFlow Single Stack Kit is a true 4" diameter under-bed exhaust system expanding to a full 5" diameter above the bed. This chrome exhaust kit was designed as a “No Muffler” exhaust system and features AccuSeal clamps for superior joint sealing. The chrome stack tips are 36, 48, or 60 Inches in length and feature high quality triple chrome plating for a killer look that lasts. For reference, a 36" stack will be about even with the top of your truck cab.
8 inch stack tips are available in straight, mitre/angle and Aussie cuts. This is a universal kit. Built 100% in the USA and comes with a full 1 Year Limited Warranty. Have any questions on what’s involved with an install? Go to our videos section to see a complete installation.
If you have a question about a stack kit, give us a call at 801-938-4891. We also offer 4 Inch, 5 Inch, 6 Inch, and 7 Inch exhaust stack tip kits and turbo-back stack kits from Grand Rock Exhaust for Ford Powerstroke, Dodge Cummins and Chevy/GMC Duramax Trucks.
Please note: Your Grand Rock stack kit will be made-to-order at Grand Rock’s facility in Ohio, so delivery time for your stacks can vary. Most of the time, kits ship within a week or two and delivery is via UPS Ground. Shipping this exhaust stack kit outside of the 48 continental United States is quite expensive, but can be arranged. Contact Us for a shipping quote.
Grand Rock PowerFlow Single Exhaust Stack Kit SPU-8SK will fit:
- All pickup trucks with a standard-width bed.
- This Stack Kit can is not recommended for installation in trucks with gas engines. Instead we recommend you consider 4 Inch Stacks or 5 Inch Stacks.
- Note: If you have a flat bed truck this kit will not fit. Contact Us to request an emailed Grand Rock stacks catalog so you can choose the parts necessary to complete your custom order.

Links
Installation Instructions
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. Important – 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.
Manufacturer Contact Info:
800-321-3674
Grand Rock Truck Exhaust Systems
395 Fountain Avenue
Painesville, OH 44077






