I found some nice inexpensive tools on Ebay. I bought some electronic calipers and a set of bore gauges, so I can measure my cylinder holes. I had absolutely no idea what to expect, since I've never torn down a motor this far before.
I meticulously measured the cylinders and found out that the bores were two different sizes! One hole was at 66.0mm and the other one was 64.5mm! My guess is that one of the previous owners burned up a cylinder, so he just grabbed a jug and piston from friend, who just happened to have a spare part on hand.
So I can either bore the smaller hole out to match the bigger hole, in effect doing a "big-bore" kit on my RD, busting the displacement out to 427cc, or I can find another matched set of cylinders with more lining, or I can re-sleeve the larger hole. Re-sleeving will cost too much money, so forget that. I found that even at 66mm, there is still a little room to bore, if necessary, so the first choice is probably the way I'm going to go. I found an automotive shop in San Jose that will bore out the hole to the larger size for $90. Not bad at all!
At least now, I know what size pistons to buy!
