Ercoupe O-200 STC Prop question

I would have your IA read the TCDS, he will find there are minor differences, but both are on the same TCDS drs.faa.gov/browse/excelExternalWindow/1...625738D005FDC79.0001

I have a different prop with an O-200 on my Alon. The engine was swapped in 1994 by a 337 field approval since the STC didn't include Alons at that point in time. The prop installed was a 1A101/DCM69/50 so that's what the FAA approved for my installation. The owners soon had it re-pitched to a 69/51. I just had to replace the original prop due to corrosion in the bolt holes and my IA wanted the prop to be the same that came off so I ordered a 69/50 and had it re-pitched to 69/51. It makes the top end of static RPM and will still want to overspeed in level flight at 2500' so could probably even be 69/52. I was unable to find any new or used props on the O-200 approved list so had to wait nearly a year for McCauley to manufacture the new one.

Already talked to Alpha, he said that back in the day they were just pulling engine and prop combos off of pre-1972 C-150's and the STC was written for that and just listed the C-150 prop for simplicity. He suggested that we talk to a prop shop.

I just figured somebody out there also has a different prop on their O-200 Ercoupe.

Using a new IA this year for the annual inspections on my Ercoupe and my friends 415-D with an O-200 STC.  This IA noticed that the STC (STC SA2628WE) specifies only one prop a McCulley 1A101/DCM 6948.  This 415-D has a 1A100/DCM 6950 - which is fine for the O-200 and is listed on the TC for the engine, just not in the STC for the O-200.

Has anyone else run into this issue before? Is everyone out there with an 0-200 running a 1A101/DCM 6948?

Thanks,

Randy Hirsch