Genuine MSD MSD-6AL-2, 4,6,8cyl 6421 Built-in 2 Step Rev-Limiter - Rotary Dials

The multiple sparks of the 6AL-2 burn in the cylinder for 20 degrees of crankshaft rotation to ensure complete combustion. Two more great features are the rev limits! This feature will help your car blast off the starting line!

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