Will this bolt directly into the factory location, or do I need custom brackets?

Factory mounting points are preserved—this tank mounts at the original bolt-down location. No custom fabrication needed.

Does the cap seal come with this tank, or do I transfer mine from the old one?

The cap assembly ships attached. If your old tank's cap is in better condition, you can swap it over without issue.

What prep is needed before I install this—do I need to flush the system first?

Pull the old tank, flush the coolant lines if they're dirty, then drop this one in. No special surface prep required on the tank itself.