...I went Distributor-LESS with Computronix. No more Rotor to Cap Spark Gap. Very Small/Short Timing Unit replaces the Dizzy. Full Voltage to 12000 RPM. No 'Spark Scatter', No Backlash. Note the difference, Runs 'Smoother' on the Freeway. I would change-over again, without hesitation. Look it up on the Net, and come out of the 'Dark Ages', in My Opinion. The Timing Unit I Received, came with the 'Steel' Gear Installed, compatible with Roller Cams.