The Curt multi fit hitch part # 13703 would work great for you as it is a multi fit RV hitch that fits 22-72 inch wide trailer frames and has a 350 lb tongue weight capacity. This will work great with the Hollywood Racks HR1700 # HLY64FR that you referenced. view full answer...
Hitch classifications aren't always exact which is why you'll see varying capacities among them. Like you noticed the Class III # C17304 has a 5,000 lb capacity and the Class III # 13703 has a 3,500 lb capacity. My best advice is to not get too hung up on the class and instead determine if the capacity is enough for your application. view full answer...