Internal Alternator Regulator Conversion Kit. This part converts an externally regulated Denso alternator to a self regulating alternator. This can be used for engine conversions or when the ECM has failed and does not regulate the charging properly. Does not work with Bosch alternator!!! Fits Denso Alternator 1989-2002
Check out the Instructions here:

Also Fits these alternators:

290-255 / 13310, 290-256B / 13185, 290-256C / 13185, 290-257 / 13353, 290-257A / 13353, 290-257B / 13353, 290-261 / 13302, 290-261A / 13302, 290-262 / 13301, 290-264 / 13311, 290-265 / 13309, 290-265A / 13453, 290-266 / 13308, 290-267 / 13280, 290-267A / 13304, 290-267B / 13304, 290-267C / 13313, 290-267D / 13313, 290-275 / 13306, 290-275A / 13307, 290-275B / 13245, 290-275C / 13354, 290-275D / 13312, 290-275E / 13354, 290-276 / 13220, 290-276A / 14869, 290-301 / 13341, 290-302 / 13442