Rear brake drum question

[Tony71c10]

So I got a 10 bolt rearend for my 84 with a posi installed on my truck. When I went to put the lug nuts I notice the studs where metric. I tried a lugnut out of my Obs and it fit perfect. I also tried to use the drums from my original l rear end but they would not fit due to the hole being too small. Bd88190 is the number on the brake drum but can't find out same match or cross reference. I figured I can maybe drill the hole bigger if I can't find a pair. Not sure if this is the right way of doing it. Or change the studs to standard but that might be too much for me to try on my own.