Well, if you keep the points on you'll need to redo the timing. Fairly frequently, too.

A timing light doesn't cost much at all, and it's a good thing to have. Most of the time, however, I set mine 'by feel'. Take it out to a stretch of deserted road, and tweak it up and down in little increments until you get that sweet spot. This varies from engine to enigne, although unworn, totally stock motors (such as what rolled out of the factory 3 - 40 years ago) could be reliably set to a fixed number. But now, with varying amounts of wear, modification, gas quality, etc the original canned number has less meaning.

You can usually get the timing close enough to start with a simple light bulb. Turn the motor over by hand until the light goes off, get that to about 10 BTDC, it should start. Then retard if it pings. Most motors seems to like the timing retarded just enough to prevent most pinging. But the occasional ping or two is not a bad thing. The occasional engine will be able to advance the timing to the point that power drops beack down, without pinging.
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I'm JohnMc, and I approved this message.