Hi, The SH or CI cams are meant for and work with the later short stroke post 1956 competition engines, alloy barrel , High comp domed piston, hemi head and enclosed pushrod tubes. If you have an iron barrelled engine , separate pushrod tubes, and a flat top piston even machining out the camcase to make fit will not really be of help. Better off with a set of roadster cams or a set of H cams if you can find them. I will look in through my spares this weekend. The cams will press out of the spindles if heated , they are identical , only the spindles different to drive the mag. Cheers, Matchless dave