[HWYSTR455]

There's also the collars/sleeves that come in some hardware kits that are for non-boxed arms. They slide in the U groove and the bolt goes through it. You're better off getting the boxed though, and if you're buying new ones, the aftermarket ones are much better.

Helwig, PST, and several others make the bar fairly inexpensive. There are exploded diagrams in a number of the resto catalogs, like PY, Year One, etc.

.