<VV> PISTON SLAP long story new problem motor

[N2VZD TIM]

I now only buy the full fin cylinder kits with pistons.I have a motor on my table now that is another mystery. A few years ago I severely overheated my Rampy with .060 full fin cylinder setup ,270 cam ,reworked heads  going up the Mohawk trail into Mass from Troy NY after buying supposed high test from a small gas station. It started pinging very hard , no place to pull over at all , with traffic behind me . So by the time I got it pulled over at the top of the mountain at a closed up tourist trap , the oil was boiling , temp light on (belt still on!) and down a quart. This motor had @2000 miles on it , My expensive  dream motor which was running great. Well it still ran OK , but uses lots of oil. I tore it down twice  last winter , checked Cylinder clearances , etc , put a new finish on the walls , new cast iron rings in , and ran it on the stand. Smoked bad from #3 cylinder only (manifolds off) So I ordered a new cylinder and piston . That seemed to fix it. So I put it back in again (I was running a spare motor). It still used a lot of oil , not that bad on smoke , but sometimes a quart to a tank!.I changed the heads to 95HP , (I had a set ready ) thinking maybe a guide situation , still bad. So now  I have it on the bench again , another similar motor in running great. I guess my only option now is new Cylinder / piston sets. I checked the PCV setup. It will get torn down again  when I am feeling better.Not sure what I will do now , but it makes a good Carb tester so far...(rebuilding a bunch of my carbs)Regards, Tim Colson