Grand Rock Dual Exhaust Stack Kit 4" Inlet For 7 Inch Tips


Part Number: DPU-7SK

AVAILABILITY: Ships from Manufacturer

Usually Ships Within: 5 to 10 business days FREE SHIPPING

Add a Reducer If Your Truck's Exhaust is Smaller Than 4"

Grand Rock introduces their PowerFlow Dual Stack Y Pipe Kit. 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 dual exhaust stack kit. (tips sold separately)

Whether you’re heading to the drag strip, tractor pulls, dyno event or just cruising Main Street, Your truck needs Stacks! 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 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 rust on seams
  • AccuSeal clamps won’t crush your pipes, leaving exhaust joints serviceable
  • All tubes are de-burred and cleaned; no sharp edges or saw chips
  • May not be compatible with other manufacturer’s stack tips

This PowerFlow Dual Stack Kit is a full 4 Inch diameter under the bed with 5 Inch diameter from Y-Pipe to the base of the stack tip in the truck bed. Grand Rock’s kits were designed as a “No Muffler” exhaust system and feature AccuSeal clamps for superior joint sealing. Grand Rock chrome stack tips (Sold Separately) are 36 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. Taller 48 and 60 Inch tips are also available. Please call for pricing. Other manufacturer’s stack tips may not be compatible with Grand Rock’s Y Pipe kit. The stack tips used must have a 5" O.D. bottom.

This is a universal kit. Built in the USA. 1 Year Limited Warranty. Have any questions on what’s involved with an install? Go to our videos section to see a complete installation.

Please note: Your Grand Rock stack kits will be made-to-order at Grand Rock’s facility in Ohio, so delivery time for your Y Pipe kit can vary. Grand Rock Y Pipe kits usually ship within 5-10 days and delivery is via FedEx Ground.

Grand Rock PowerFlow Dual Exhaust Stack Kit DPU-7SK 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.


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 90° 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:


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