What to Do With Holes in A-Frame?

I would get some bolts with the same dia. and thread pitch and put them in the holes along with washers. Go an autobody supply shop and get a tube of black "seam sealer" and seal between the washer and frame and around bolt head to keep water out. This sealer will be under $10 but you'll need a caulking gun. They might have a small tube available somewhere but I've never looked. You can buy washers and bolts with the same gold cad plating color as the Reese ones if you want.

Am not a structual engineer but I would say that the A-frame "tubing" is a low stress area where the brackets go and there will be no problems unless it looks like swiss cheese for some reason. There are lots of other places on your frame that are much higher stress to worry about first. I'd be more concerned about keeping water out.

Thanks. The sealant idea is great as it will last longer than rubber plugs due to UV exposure alone.

The side walls is the structural part off the a frame not the top or bottom, if concerned you could have plates welded to sides but they have to be cut at 45 degrees at end for welding or the weld will further weaken frame.

Get some automotive body filler. Fill the holes, sand, paint. Gone forever and it has worked on cars for decades!

You'll soon forget that there were ever holes there.

I just painted my holes and moved along. The front of the frame rails are wide open and I am not concerned about them in the least