Classic/Antique Car Repair: mechanical, 1959 chevy biscayne, valve seals

Question
I HAVE A 1959 CHEVY BISCAYNE, WITH A 235 6 CYL AND 3 ON THE TREE,WITH A REBUILT HEAD W/HARD SEATS ON THE VALVES. MY CAR RUNS AND DRIVES FINE BUT I HAVE OIL AND DARK GRAY SMOKE COMING OUT OF THE REAR EXHAUST PIPES. WHAT MIGHT BE THE ISSUE?

Answer
Robert;
Hea- well I hate to say it but you might need new valve seals, I would first do a compres. test on each cyld. to see what you have for cyld.psi. you can get some oil fouling type plugs that might help a bit too. and there is a valve sealer addative that might help the valve seals to swell up a bit but the only way to fix it if it is that bad is to get a valve job.do your spark plugs get all wet and oil fouled ?