I use a silicone bead around the sealed edges of each light segment. I don't like drilling the hole. I find that the silicone seals it up permanently.
Maybe you also got the wrong light housing. The 84 down 6 panel light looks
the same as the 85 newer light but the bottom corner parking light has different pin locations in each light housing. They are not interchangeable.
Plus the older housing uses a 67 bulb in that location the newer light uses
a 1157. The slight location change of the pins is only about a quarter inch
difference. Drove me crazy till I figured out that some jerk had installed
a 1980 light housing on my 86 244DL.

My aftermarket front turn signal lenses for my 86 244DL have already faded and they are only about 9 months old. I've had other issues with Scan-Tech. You can
check my post from a few days ago.

Dave 82 242ti 280k mi.