The 1250 is actually 3/8”-18 straight thread. It uses a gasket that I consider to be a PITA. Use a 3/8” pipe plug with a little sealer on it. Don’t go go all Hercules on it. The pan is aluminum. Just snug it up good with some sealer.
Try the sponsors at the top of the page.
Kirk engines sells a magnetic drain plug for 3 bucks. I thought Charlie sold drain plugs also, but I could not find them.
All the sponsors do not appear every time. You have to open different threads/pages to see them all.