TMW Off-Road
Factory UTV
Axia Alloys

Sport UTVs:
Polaris RZR XP 4 1000
Polaris RZR XP 1000
Arctic Cat Wildcat
Can-Am Maverick
Polaris RZR XP 900
Can-Am Commander
Yamaha Rhino
Kawasaki Teryx FI 4x4 Sport
Polaris RZR S

Product Review

SPD Custom Headers

We have decided to ditch the off-the shelf Hooker Headers, for a custom designed set from Specialty Design Products (SPD).

Original Setup - Hooker Headers
Original setup - Hooker Headers

The car came with a set of Hooker Headers (Universal SBC Shorty - 2466).  They did the job fine, but don't have equal length tubes, and are probably a bit restrictive for our 410 cid engine.


Why we chose SPD?

SPD not only builds custom exhaust systems, but they also manufacture many of the exhaust components (collectors, transitions and flanges) that other exhaust fabricators use.

They use large radius, wrinkle free mandrel bends to ensure high flow and minimize any turbulence. Headers are available in 304 or 321 Stainless Steel or Mild Steel and are tig welded. CNC machined 3/8 thick Header Flanges are included for maximum sealing and proper cylinder head fit. Headers are offered with either 4 into 1 Merge collectors, for maximum power potential throughout the full RPM range, or 4-2-1 Tri Y collectors, for maximum low to midrange torque.

And to top it off, they come out looking like a piece of art.

The Installation

31" equal length tubes.  1 3/4" stepped to 1 7/8" tubes.

SPD Custom Headers   SPD Custom Headers
New SPD header

SPD Header vs. Hooker Header
Old vs. New

Changing to a Magnaflow 3" straight through stainless muffler This should open it up a bit over the baffled DynoMax design, but not make it much louder. The muffler's we used are Magnaflow part #14229 - 5" x 8" oval, 3" in/out.

Dynomax Muffler
Dynomax Muffler - Notice 2 1/2" in/out

Magnaflow Muffler 5" x 8" (3" straight through)    3" Magnaflow 5" x 8" Oval Muffler
Magnaflow Muffler

The Results

The entire exhaust turned out beautiful.  Very pleased with the fit and finish.  Exhaust sound has a bit more growl to it, but still acceptable.

We will have it on the dyno and in the dunes soon.

Contact Info:

Specialty Products Design
11252 Sunco Drive
Rancho Cordova, CA 95742

Phone: (888) 778-3312

Back to Product Reviews

Back to Sand Dune Guide

Long Travel:
Can-Am Commander Long Travel Kits
Kawasaki Teryx Long Travel Kits
Polaris RZR Long Travel Kits
Arctic Cat Prowler Long Travel Kits
Yamaha Rhino Long Travel Kits

Favorite Sites:
UTV Guide
Crowley Offroad
UTV News
UTV Models


Dune News | Trip Reports  |  Advertise  | Contact Us

Worldwide Dunes  |  Closed Dunes



Copyright 2010 Crowley Offroad LLC. All rights reserved.
No images or content represented on this web site may be copied, stored, manipulated, published,
sold or reproduced in whole or in part without express written permission.

OpenCube AJAX Components

hits counter