adding a transmission temp gauge on P30 chassis

I installed one on my 1989 Pace Arrow P30 chassis. I removed tranny pan to check clearance inside. Drilled hole while pan was off. Welder welded nut to pan. Screwed gauge into nut using permatex sealer. Worked great. While I had pan off drilled 2nd hole and 2nd nut welded to use as a drain. I could then drop an empty pan. You must drop pan to check clearance because it is pretty crowded inside tranny.