[Rick Parker]

I can't help you with the catalog numbering but if you are attempting to find the ratio, here is how to do it. Use your calipers. From the side view and in one straight line, measure from the center of the pivot to the center of the pushrod hole. Do the same from center of pivot to the center of the roller tip axle. Divide latter measurment by the first; it should work out to be very close to 1.6 which is Fords standard ratio unlike Chevrolets which is 1.5. Sometimes the ratio is actually stamped on the rocker arm.