Chevy Tail Lights leak

[Moonmanvt]

Our 2001 200P tail lights were leaking since the previous owner. I decided to replace the gaskets. Glo-Brite 181 and 182 are the light numbers, but Glo-Brite or Chevy does not sell a gasket...I would have to buy the whole light ($143 each from Chevy ~$45 each from Glo-Brite). I removed and reset each tail light so it was as close as possible to fitting properly. Once set, I used some 3M "crystal clear "3 hour setup" window caulking. We had heavy rains this weekend and....no leaks! I realize I will have to slit the caulking to replace bulbs (no rear door) but it's a small tradeoff for a dry sleeping area.

[Malysoun]

Just a theory here, but couldn't you use painters tape on both sides of the light/opening, put the caulking over that, wait for it to set and then remove the light and peel a new 'gasket' off the tape?
You might also consider single sided foam weatherstripping tape cut to size.