help! lights pulsate and wipers speed up

The surest way to check this out is to use a voltmeter and check the battery voltage at low idle and fast idle with the battery fully charged. And measure the voltage between the battery + and the alternator output at fast idle. With that data, it will be a lot easier to help you. And a voltmeter will be a worthwhile tool on these older cars; you can troubleshoot a lot on them with one.

As mentioned, check the grounds all over; the new regulator may need a bit paint scraped off and the points where it attaches cleaned with a wire brush. The pulsating lights point to that (or some other poor connection) being a good probability. And the attaching screws may need to be replaced with bolts, or larger lag screws if the attachment holes are wallowed out.

BTW, with the original system, some change in wiper speed and headlight brightness is normal; we can't see just how much it is on the i-net. But the pulsating is abnormal.