1997 502 MagMPI Distributor module
 

Does anyone have a part number for a replacement module that I could get from my local auto parts store.

If yours says 10482830, 16139399 on it, then the ACDelco Module is D1956A

And yes, the D1956A crosses with Merc Catalog Part# 811637, 811637T which is for your engine.

The ACDelco D1956A is available from Amazon and other retailer's for about $70.00.

Don't forget good heatsink compound and read how to apply it.

ACDelco D1965A GM Original Equipment Ignition Control Module
by ACDelco
Link: http://a.co/cIXVnQA

The part number I am coming up with is 8M0123099?

From Mercruiserparts.com 8M0123099--MODULE Superceded From 811637T

Much appreciated info. Thanks