Inboard newbe

[boardman74]

They are a direct bolt on.

Since the towers are power coated the threads are usually covered. We ran a tap thru all the holes prior to installing. Good idea for the speaker holes also.

[NHarp1]

I agree, the tower threads usually have paint/powder coat in the threads. I would run a TAP in the threads to clean out paint before running the bolt in.
SAMSON instructions even suggest making sure the threads are free of paint if the hole if a previous rack bolt has never been installed.