This is the bolt that holds the alternator to the factory alternator adjustment arm. It is loosened to adjust the tension on the fan belt. This bolt can also be used to hold the alternator to the lower mount bracket on the block. Sold individually, 3 required per car.
Datsun 240Z, 260Z, 280Z, 280ZX
Datsun S30, S130
1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983