Got the new TR3 rocker cover today to replace the TR4 cover I have. The filler tube diameter on the 3 is bigger than the tube on the 4 so I can't use my cap unless I grind down the tube. New TR3: 1.519 in, old TR4: 1.478. Are the caps model specific? Also, the new cover has been re chromed. It's a good job, but I have some peeling chrome on the inside of the cover. I've removed most of the peeling with a scotch brite pad and I'd like to seal the inside with some hi temp engine rattle can clear because I don't like the idea of it flaking off into the oil flow. Anyone see any future problems here?