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IMM Engines: How To Build A Pump-Gas 620hp Small-Block Mopar

60hp Small-Block Mopar

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We first teamed up with Brian Hafliger of IMM Engines in Indio, California, in our June ’10 issue. We documented his build of a stout 408ci 360 stroker that made 485 hp with cast-iron RHS cylinder heads. In the months since, we kicked around the idea of investing a little more, going bigger with the cylinder heads and cam specs, and shooting for 600 hp with the same 360-based engine. After several months of gathering parts, we drove back out to the Coachella Valley to watch this version come together and run on IMM’s DTS dyno. We were thrilled to see the horsepower numbers soar past our goal of 600, with the needle finally indicating 621 hp at a thundering 6,800 rpm. Torque numbers weighed in at an equally impressive 541 lb-ft at 5,100 rpm. In a 3,500-pound Duster, this engine will do low 10s at the dragstrip all day long and sound awesome doing it. Interested in how IMM pulled this off? Let’s get to the build.

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1 comments
jcmmurray
jcmmurray

Could I get the grind numbers for that cam ?

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