oem hitch bolt thread issues HELP 2000 OBW

[000utback]

Men! I am installing a Subaru oem hitch receiver on my 2000 outback wagon. The instructions said use a hole saw to make 2 1.5" holes in the bottom of the bumper cover. That part worked. The bolts to mount the oem hitch go up into nuts that are factory welded onto the bumper supports. The hitch also bolts onto the factory towhooks. Well. I am having a terrible time running these 5" bolts vertically up into that welded nut on the bumper mount. The Subaru bolt pack (L1010LS100) lists the bolts as 1/2 x 5". They turn terribly hard and the threads are getting messed up. Looks to me like they're 1/2-13 US standard bolts. Aren't Subarus metric? I don't have a metric bolt here to try, but I wonder if the M12x1.75 would run right up there.

 

Why would Subaru put 1/2-13 bolts in their package? What do you guys think - should these be metric bolts or us standard?

 

Thanks in advance for any comments. The car is up on stands, the muffler is hanging loose, and the hardware stores are closed.

[J A Blazer]

I just installed a Draw-Tite hitch on my 2000 OBW and it was a piece of cake; however, my installation involved fishing carriage bolts in through existing holes in the 'frame rails' (for lack of a better term), rather than screwing them into 'welded' nuts.