Yes, I wasn't distinguishing the B; what I have is really a 60IIIB G8 (not all B's had G8 carbs).
The problem with the holes on the exhaust ports was that if you put on a muffler, the muffler strained the exhaust port and it would fail. And we all use mufflers now, so the holes are an accident waiting to happen. Plus you have to cover them up somehow or the muffler is useless anyway.
My 60 II, with a Perry carb, turns a Rev-Up 12x5 at 11,000 rpm, which is about the same as a typical 50-something four stroke. Weight with an old Enya muffler is 17 ozs, so it's a little heavier than the 50+ four stroke. Lengthwise it is shorter, and I like the sound, so it will be useful. Mine will go into an old VK Navajo, which is a nice way to use an engine like this.
My IIIB is slightly heavier and I will use my Bisson strap-on muffler. Total weight is about 18.5 ozs, but it will have much more power than the II. Haven't run it up yet. Jim