I'm no expert but I think you answered your own question.... time to sand those pits out (sand paper or greaseless). I just bought my greaseless and so far the testing is pretty encouraging. Do test on a piece of scrap by the way.
I
think the casting material on an '82 will be fine but it's possible that the casting itself is porous. Only one way to find out. If it is porous then I guess the only answer... well two answers.... is to live with the pits or send the pieces to the chromer.
Good luck on it bro... I'm working on my XL this winter.
