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The primary factor is heat. The turbo engine will create hotter combustion temps, so you need a colder plug. Start with NGK BP8ES or equivalent.

Quote:No need to downgrade. NGK make a full range of plugs I dare say as good as or better than Bosch.

After running the 8s, inspect the plugs for proper combustion (tan color). If glazed white, you need to go colder. If black you need to got hotter. Once you find the right plug heat range, buy a double-platinum version so they will last a long time. Don't bother with regular platinum.

If you have a points distributor, consider upgrading now to Datsun electronic ignition. Otherwise keep the dwell set correct using a dwell meter every 3 months and replace the points & condensor every 12 months.