Packing Big Block into Chevy Turns it into Super-Truck!

GM’s big-block engines don’t get a lot of love, but this 8.1L motor finds newfound appreciation in ’86 K30 military truck.

General Motors is iconic for offering high-performance engines for enthusiasts looking to increase the performance of their project car. The LS-branded family of engines are a huge hit with off-roading enthusiasts, while hot-rodders prefer to go with the old-school big-block motors. This leaves the big-block Chevy 8.1-liter engine in a precarious position, as they’re not popular, but can be bought for little money.

Four Wheeler decided to go against the grain, and place an 8.1-liter engine into their 1986 Chevy K30 military pickup truck and has nothing but good things to report. Well, almost nothing but good things, as the outlet found a rear main seal leak after putting the engine in its place, but that’s a possibility when using a motor from a junkyard. Aside from that, Four Wheeler is happy with the big-block.

“The engine runs smooth and is grunty,” claims Four Wheeler.

The motor was found in a 2003 Chevrolet Suburban 2500 4X4 and was bought for an affordable $1,500. The motor came with a 4L80 transmission, which was rebuilt by Gearstar. Before putting the powertrain into the truck, Four Wheeler removed the factory wiring harness and sent it to Tilden Motorsports where it was simplified and the ECU was reflashed for the new engine.

Besides needing to modify the frame for a decent amount of clearance, Four Wheeler claims that firewall clearance wasn’t an issue, the 8.1-liter engine fit into the engine bay without any hiccups. The outlet even managed to use the factory air intake from the Suburban and an Optima YellowTop battery.

Bolting the big-block engine into the truck wasn’t the only modification Four Wheeler did, as the outlet installed a fuel tank and filler neck from a 1980s Suburban, which sits behind the rear axles and forces the spare tire to sit in the bed. Thanks to Tilden Motorsports, the outlet was also able to use the drive-by-wire throttle system from the Suburban, as well.

If this sounds like a cool build, that’s because it is. It’s unique and the finished product is an off-roading beast. To get some more information on Four Wheeler’s build and to check out in-depth pictures that follows the transformation, head over to outlet’s story, which you can find here.