Exhaust ports are the same.
Dizzy is a little different. The smallport one has only the single reference tooth while the bigport one has 4.
Cams, the bigports are 240 deg, 7.5 lift, smallports are 232, 7.1
Timing gears, buckets, shims, are also identical. I'm pretty sure the valves are also the same.
Eddie.
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