How do I set the timing on a 340?

To set the timing on a 340 engine, first ensure the engine is at TDC (Top Dead Center) on the compression stroke for the number one cylinder. Then, loosen the distributor hold-down bolt and rotate the distributor until the timing mark aligns with the desired advance setting on the timing tab. Finally, tighten the hold-down bolt while making sure not to disturb the distributor position. Always double-check with a timing light for accuracy after adjustments.