This 630-HP Drag-Racing Postal Truck Has a 6.0-Liter Small-Block Engine

If you see the owner on the road towing it on an open trailer, stop and talk to him about it. Everybody else does.

byKristin V. Shaw| UPDATED Jan 31, 2021 7:15 PM
This 630-HP Drag-Racing Postal Truck Has a 6.0-Liter Small-Block Engine

According to David Stacy in Laporte, Indiana, there is only one drag-racing mail truck in the U.S., and he owns it.

Former aerospace maintenance technician (now LS swap specialist) Stacy hauls his one-of-a-kind vehicle from his home state all the way down to Florida, Texas, and everywhere in between. He was already an enthusiast and had attended Holley

LS Fest for several years when he had the idea to boost a mail truck. It took him two years of searching to find one he could purchase, and it turned out to be right there in his hometown.


The woman who owned the mail truck was only a few months away from retirement from her rural route, and she agreed to sell it to Stacy, complete with the decals the mail carrier’s husband had added to make it look very similar to the government-owned U.S. Postal Service trucks; and Stacy kept it that way after he bought it. This Grumman LLV has the usual right-hand-drive configuration and came with a GM Iron Duke 2.5-liter engine that Stacy says wouldn’t go faster than 65 mph.

First, Stacy swapped the Iron Duke for a stock bottom end 6.0-liter LS and added a 6L90 transmission. Then he upgraded to an LSA supercharger that was tuned by Fasterproms in Florida, bringing the mail truck to 584 horsepower and 600 pound-feet of torque. At about 4,000 pounds, the truck is a little top-heavy, and its size requires Stacy to use an open trailer to tow it from event to event. The funky postal truck generates a lot of attention, which benefits both Stacy and his sponsors, generous parts manufacturers that help him keep the LS Postal, as he calls it, at the top of its game. He’s about to have the blower ported, which will nudge it up to 750 hp.

“The engine can hold up to 1000 [hp] if it were done right, but there is a fine line when you’re building a truck like this to ‘where do you want to stop?’” Stacy told me. “It’s fun to drive and gets a big crowd.”

The fastest he has run in the boxy-framed mail truck so far is 108 mph. The Pony Express has nothing on the LS Postal, and while no mail carrier can (or should) be tearing up neighborhoods at that clip, it’s fun to see the traditional mail truck on the track.

Stacy has a whole schedule of events where he puts the LS Postal on display and occasionally participates in exhibition races or doughnut competitions. He favors the Cleetus and Cars events all over the country and he’s eager to get back on the road for the next event in Houston in a few weeks. What's next for the LS Postal? Stacy isn't sure yet, but he's guaranteeing an on-time delivery. 

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