Floyd nailed it, including the characteristics of the ends of the two types of original bolts. I also agree that the Drake bolts (at least those of a few years back) do fit.
Also, beware that some original bolts have been bent (the threaded shank relative to V-shaped head) as a result of run ins with trees, fire hydrants, other cars, etc. They are very difficult to straighten. If you buy some from photos, insist on a side view and another side view front to back.