I just recently did this job.
Jabsco claims in their literature the holes on the new part align with the holes on the older style base. They lied. The old style has 4 holes the new one has three holes. Also, be careful. They changed the base’s design and not the part number.
In my case, I did not find the backing plate extended to the area needed for the new bolt placements. This was very evident when drilling the new holes. I filled the old holes with epoxy (I color matched the brown).
I used stainless steel threaded coil inserts secured with resin for the new screw positions. Then screwed the bolts into the inserts.
With best regards,
Sailing Vessel - Cream Puff - SM2K - #275
Currently cruising - Tahiti, French Polynesia
main@AmelYachtOwners.groups.io [mailto:main@AmelYachtOwners.groups.io] On
Behalf Of Robert Nilsen