Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
As Bryan has already said, not worth the trouble with the pistons , a engineering shop can charge around £45 just to measure up and then tell you that you then need a rebore. You can get a good oversize set from Japan for about £110 including post. Get a good engineer to rebore at a piston to bore clearance of one thou , if anyone tells you that this is too tight, walk away as, they don't know what they are doing.If the sump pan is leaking from the drain bolt, look for a good secondhand one that has not been welded. Never torque a sump bolt more than 20 ftlb on these old girls or they will crack the pan