Naturally Aspirated 598 cid Big Block Chevy Engine

Aug 10, 2023

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We’ve always been impressed by the engines and machine work coming out of Gibbons Motorsports in Mooresville, NC. We last spoke with shop owner Pete back in 2020, so when we got a chance to visit the shop earlier this summer, we jumped at it. What was started by their father Peter years ago, has for the last several years, been taken over by sons Pete and Jake, and despite their younger age, the top-notch engine quality and knowledge has certainly continued. During our visit, we were treated to a shop tour and the details of a few engine builds in progress – one being this 598 cid big block Chevy engine.

According to Pete, the 598 cid big block Chevy was an engine going together for his younger brother Jake and his competition needs. The 598 is an all-aluminum, pump gas, hot rod motor taken to the extreme.

“It’s got BB3 Brodix heads, a Brodix block and Brodix manifold – everything from them,” Pete Gibbons says. “Internally, it’s got a Molnar crank, Molnar rods, JE pistons, all coated bearings, a 55mm COMP Cams camshaft, .937” Crower bushed lifters, and it’s got a Jesel shaft rocker system on the head, as well as Rev stainless valves and Trend pushrods. It also has an Xceldyne belt drive and a Dan Olson oil pan. It’s overkill for a street motor and it’s just 10:1 compression. We just kept it down for running pump gas and we are running the coil pack stuff from MSD. He didn’t want the typical LS swap, so we made a big block LS motor with the LS firing order cam and EFI coil packs – something different.”

According to the shop, the LS firing order is something Gibbons goes to often for their endurance race stuff like Dirt Late Model engines and much of their drag race stuff as well.

“It sounds different in the big block,” Pete says. “It sounds cool. And with the coil packs, the thing idles smooth as can be and makes 900 horsepower just NA at 10:1. It’s got some good stuff inside, good heads and it’s light, which is what we want.”

Sitting on top of the 598 big block is a Holley Sniper EFI unit, which is made to look like a carburetor setup.

“It’s their Stealth unit, so when you have an air cleaner on it looks like a carburetor, but it actually does have injectors in the bowls and it runs off the cam sensor in the back,” Gibbons says. “It’s basically an electronic carburetor, it’s a 1440 cfm throttle body, basically. It’s more than enough. He went for the gold color to give it an old-school look because the engine is going in a ‘69 C10 short bed truck.”

While this 598 big block is capable of some serious horsepower, Pete says his brother Jake plans to use the C10 primarily on the street.

“The C10 is a street truck,” he says. “[Jake’s restoring it and doing frame off work on it now. It’s got a 4L80 overdrive transmission going behind it and it’s going to be a pretty rowdy street truck.”

With 900 horsepower at the ready, we have no doubt Jake will be having some serious fun in his big block Chevy-powered C10, and we’re a bit jealous.

Engine of the Week is sponsored by PennGrade1, Elring – Das Original and NPW Companies. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].