Erik:
Keep in mind that your boat was repowered in 92 with a 41B and a 1:95 outdrive. I would stick to the 1:95 and adjust your prop accordingly as suggested by the experts (me not included) on this forum. I found a couple more receipts and indeed the outdrive was rebuilt last year by a authorized Volvo repair shop here in MDR. I spoke to Karl who remembered it to be a 1:95 and he suggested as did Mike, (No Slack) that the 1:78 is used with the higher horsepower diesels. I also found the receipt for the u-joint service gone by John (Blackmans mechanic) he also noted that is was a 1:95. Both repairs were done last summer.
Mike