Delivering the Goods: LS Powered USPS Mail Truck With Anger Issues

Just when you thought you’d seen it all, along comes an LS-swap so unusual, that you have to step back and say, “Holy crap. That’s pretty freakin’ wild.” Such is the case with David Stacy’s obtuse unicorn of a side-project, a U.S. postal delivery vehicle packing all of the frumpy OE styling one expects to find in a mail delivery truck. But with a few tasteful external twists, and a hefty bump in power beneath its boxy frame, Stacy’s boxy build delivers the goods and then some.
Flash-back about two years and the Indiana native was driving with his wife when a mail delivery truck pulled out in front of their vehicle. While the couple avoided the collision, David was “struck” by a brilliant notion. Why not build a mail truck for LS Fest?
This proved to be easier said than done, as it took nearly two years of hunting before David finally found a USPS truck for sale, which ironically happened to be in his hometown. Considering how many mail trucks can be found on the road any given day, one would expect these things to be a dime a dozen. This was a bit of a shock to Stacy, who admits to collecting parts as early as January of 2019, well ahead of that fateful day in June, when he finally took ownership of the mail truck seen here.
But while it took two years of searching and planning, once the truck was in David’s possession, the entire build came together in just three short months. While taking the truck to the 10th annual LS Fest remained the primary objective, there was one major ulterior motive. Stacy laughs and confesses, “My goal was, I wonder if I can get it on a t-shirt?”
Stacy admits that sourcing all of the necessary parts and making them all work together was another enormous challenge. Being that no one in history has attempted such a swap, this build was part trial and error, part fabrication free-for-all, as the attached pictures illustrate.
Then there were all of those unexpected snags one encounters when building something from the ground up. For Stacy and his postal truck, the biggest hiccup came via the Chevy Silverado 6.0-liter that had been selected for powering the platform. After successfully installing the engine and turning it over for the first time, Stacy came to the gut-wrenching realization that the V8’s cam bearings were shot. Forever the optimist, Stacy tells us that this allowed him to completely rebuild the motor, which, as the following paragraph illustrates, was a fairly significant overhaul.

6.0-liter LS V8 in David Stacy's USPS postal truck

The Silverado 2500 HD 6.0-liter LY6 stuffed inside this shipping container features a rebuilt bottom end with a Griffin radiator, Brian Tooley Racing (BTR) LS3 stage 3 cam, LS9 head gaskets, modified heads, dual valve springs, and an upgraded trunnion kit. There’s also a Holley mid-rise intake setup with a 90mm LS3 throttle body, 42-lb Holley injectors, and a cold air intake off a 2012 Camaro SS that Stacy modified to fit. Spent fumes are projected down the insides of two Stainless Works long tube headers, before reaching a Summit Racing X-pipe, and dumping out of Magnaflow mufflers. A Current Performance Wiring plug-and-play custom harness powers and controls it all.

Stacy’s mail truck sports a 6L90 with an 8.8 Ford Explorer rear end that’s been filled with 3.73 gears and a limited-slip differential. There’s also a custom driveshaft running front to rear, along with a Derale transmission cooler, and a Circle D Specialties 3400 stall billet torque converter. Curious as to his decision to run a torque converter from Circle D Specialties, we asked Stacy what his thoughts were on the company’s products.

“They had the best reviews, their customer service was top-notch, and their products work great as described,” Stacy explains. “I will be getting a triple-disc converter from them when I upgrade to a supercharger this winter!”
When asked what other winter mods he might have in mind, Stacy informs us that he plans to install an LSA blower with a 2.55″ pulley, and a BTR Stage 3 blower cam. He also is looking to upgrade the mail truck’s brakes to a Wilwood kit, both front, and rear. 
But for now, Stacy seems happy that he was able to meet his deadline and catch some attention at LS Fest. His use of  Colvert Racing Caltrac traction bars and a Summit Racing line-lock setup helped him keep his dished 17-inch wheels planted and pointed in the appropriate direction on the strip, and he even was able to compete in the burnout competition.
“I have met a lot of people after I built this truck,” Stacy humbly admits, “I want to thank everyone that has helped, everyone that I met, and my family for helping me and supporting me. I can give people hope that when you put your mind to something, it can happen, take your time, plan it out, and it will come together.”
We look forward to seeing what David Stacy’s LS-swapped postal truck can do with a blower on it come next spring.

About the author

Micah Wright

Raised on LEGOs by grandfathers who insisted on fixing everything themselves, Micah has been a petrolhead in training since age four. His favorite past times include craft beer, strong cigars, fast cars, and culinary creativity in all of its forms.
Read My Articles

Late Model LS Power in your inbox.

Build your own custom newsletter with the content you love from LSX Magazine, directly to your inbox, absolutely FREE!

Free WordPress Themes
LSX Magazine NEWSLETTER - SIGN UP FREE!

We will safeguard your e-mail and only send content you request.

LSX Magazine - The Late Model GM Magazine for Camaro

We'll send you the most interesting LSX Magazine articles, news, car features, and videos every week.

LSX Magazine - The Late Model GM Magazine for Camaro

LSX Magazine NEWSLETTER - SIGN UP FREE!

We will safeguard your e-mail and only send content you request.

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...



Corvette Enthusiasts

Performance Driving

Engine Tech

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

  • Corvette Enthusiasts
  • Performance Driving
  • Engine Tech

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Thank you for your subscription.

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Thank you for your subscription.

Loading