Spark Plug Confusion - Supra manual vs. Indmar manual

1999 Supra Comp with Indmar 5.7L EFI engine

Looking to swap spark plugs.

I first referred to the Supra boat manual which states OEM plugs are AC Delco 41-932. I cross referenced to NGK and found NGK TR55IX. I purchased the NGK plugs and installed (but have not started the engine).

However today, I decided to check the Indmar engine manual and it states OEM plugs are AC Delco MR43T. Cross referenced those to NGK and they came up NGK BR6FS.

Not sure what to do. I tend to trust the Indmar manual over the Supra, but thought I would check with the Supra gurus here to see if anyone has any guidance on this.

I'm grateful for any guidance you can offer.