That's what I do anymore. Relying on the threads of the fastener to do their job like they originally did is sketchy at best. Especially after new paint is added to the mix.
I don't take much, and then I spritz some paint on the area once the ground is re-fastened.
Check your main battery ground cable first. Is it just a single cable going to the engine block? Or does it have an additional wire going to the body?
Most people leave that last one out because they don't replace a ground cable with an exact match to the original. Ford had few enough grounding points as it was with Broncos, so adding some new ones in addition to reconditioning some originals is a good practice.
The alternator on a '77 had a small ground wire attached between the alternator body and one of the mounting screws of the voltage regulator. This was relatively important, but it's also possible that your original regulator is just not capable of working as designed anymore. Maybe it was before you pulled stuff apart, and simply decided to give up the ghost at that time.
I call them "coincidental failures" and they happen all the time on our older vehicles.
Along with the engine/body ground, an additional ground strap/wire between the back of the engine and the firewall never hurt anyone. It can only help with all this stuff.
Is the engine painted? If so then you might consider either scraping the paint off of the surface that the alternator touches, or add a secondary ground wire between the alternator and engine block. I don't know that it has to ground (maybe Steve83 can shed some light on alternator grounding), but that's a generally accepted assumption.
One other common area of "ground failure" is the radiator core support. It's welded to the rest of the body, but between old age, rust and new paint, it often loses contact with it's old friends the fender aprons.
Since the headlights and the turn signals/running lights ground to this panel, creating a jumper wire between the core support metal and the rest of the body (where the main body ground is, is not a bad spot) will guarantee happy camping in the headlight department.
Won't necessarily get rid of the pulsing, because that's more of a charging system issue directly. But it can only enhance the workings of the lights.
And speaking of enhanced workings... How do your wipers and dash lights and such work?
Back to the regulator, personally I would replace it with a high-quality new one (if there is such a thing anymore?) and save the original in a box of original parts in case you ever want to show it or sell it.
Paul