Many Formula Fords use a side-mounted oil pump with a mechanical tachometer. The tach is usually driven from the front of the cam by mounting a tach drive gearbox on the front timing chain cover. This drive flange mounts to the camshaft using the stock camshaft sprocket bolts without any modification to the camshaft or sprocket. The slot is machined to be a perfect fit for the drive dog on our FF1600 Tach Drive Gearbox (Part No. 166-20), sold separately.