base timing keeps advancing by itself...

Your dampener wont know where tdc is if the ring has spun.

What ignition box, 4 or 5 pin?

Pull the distributor, mark the gear inline with the slot...run it... pull distributor again and see if the line is still inline with the slot.

If you dont check that stuff, like verifying tdc on the dampener... we're done. Get a book and disregard it 'instead' of us.