"How do I time a B230 engine?"

Depends on the year. '85-'88, disconnect and plug the vacuum line at the Ignition CU near washer tank. (See Note below)
Set to 12±2° with timing light on #1 plug lead as usual.

From '89 up there is no adjustment, The ICU handles the timing.

NOTE: You can leave this line plugged if you get high NOx readings in emissions test and the other readings are acceptable. It's been found that the ICU's default advance curve does well on it's own—where the vac advance (to the point of knocking, then retard) can cause excess NOx. Not a guaranteed fix but has worked for many.
More info here.

I recommend the Bentley 240 Service Manual.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.