Unless US Tower recently changed their methods, they sell their base mount bolts as straight galvanized ALLTHREAD stock with double bolts on the immersed end. They stopped using J bolts a few years back. You can make your own j (or L) bolts if you feel the need. I didn't in my base for a HDX572. 

John Owens - N7SEJ

_____________________________________________________________
Netscape. Just the Net You Need.