Just bought a used tow hitch, need mounting hardware

[Legend11]

I just bought a Draw-tite class 3 tow-hitch off of craigslist for $50 last night , but I need mounting bolts/washers. It looks like the 2 tow hooks needs to come off (3 bolts each side). Can I just use the existing bolts and buy 2 more? Also what grade strength of bolt would work? 5 or 8? I see too many conflicting things online. I won't primarily be towing, but I do like the option. I will mainly use for a bike rack, and cargo/small trailer for camping gear.

Thanks!

[Hawairish]

If the hitch uses the same positions as those tow hooks, don't see what you couldn't re-use those, or at least use them for sizing reference. Being metric bolts, you'd likely want Class 10.9 (Grade 8-ish equivalent) if you have any potential to use the hitch for towing or recovery.

Also, would you mind taking a pic of those tow hooks? Not sure I've seen them before.