piston identification?

[blackdog]

I am in the process of disassembling a '66 305 dream, to put it back on the road in 'good' condition, not a full concours resto. paint and a few new parts...

anyway, finally got the pistons out, (one bore had rust in it) and they have no markings on top, except the direction arrow. can i safely infer from that that they are std size? i'm guessing so, as the bike only has 5200 miles on it, according to the odo. appears to have been 'just parked'.

thanks, all!

jim h.
duvall, wa

[48lesco]

Best way would be to measure them, but if there's no other marks on top and it looks like you're the first one in, they're probably std. If you're just going to hone the bores and reuse the pistons, I have a set of std rings (13020-275-000) with 1000 mi on them that I would let go cheap. I'd say be careful tho after you clean up the cylinders that you don't have more than about .003" clearance or you'll hear those pistons.