[Mart]

Would I be completely off base by thinking, if it were me, If I could find a piston, I'd reuse the existing rings? In my mind, the rings are bedded to that bore equally as well as the other 7 piston/ring/bore sets.

It does beg the question, though, why did that one let go? If due to lean mixture, there should be 3 other pistons that might have been getting fuel and air from the same side of the carb. (Assuming single carb). If it is a defective piston, what is to say the others are not on the verge of letting go?

If you can find one piston, all well and good, cross your fingers and carry on. If not it might be worth going with a new set of pistons and rings and a freshen up of the bores with a hone to seat the new rings, or go .100 over on all 8 with a new overbore.

Personally I'm a chancer and would just change the 1 if a replacement could be found, but that might be the clincher. You might not be able to find just 1 and be able to weight match it to the rest.

Good luck with it, though.

Re the valves, you should be able to pull the guide(s) down with the correct tool and withdraw the whole assembly in one go. Remember on the inlets it is often easier to push the guide down with a suitable lever.

You push the guides down just a bit to get the horseshoe clips out.

Mart.