28SI Alternator Pulley Fitment Issue

[Neto]

so I bought 2 Delco 28SI locally (180A versions) to replace some old alternators on my 6CTA (Delco 10D) on my “project boat”….. I dont know why the previous owner used these old alternators but they did not seem to be working and needed external regulators.. I removed the pulley from these alternators and attempted to install on the 28SI and they dont fit… The pulley inner diameter is smaller than the 28si shaft..

Does anyone know the part number for the pulley that I need? I need to try to source this locally since i need to get this installed asap..

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[Neto]

thanks, I just bought it from the site… i doubt i would find this anywhere in Puerto Rico…

[Gene Fuller]

The Cummins part number is 3918275.

[Author]

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