Re: 1969 merc 1250ss vs 1984 merc 115
The 84-88 115 had about 135 at the flywheel, so I doubt that you could notice a 10hp increase. From 84 on, Mercury went to the industry standard mounting bracket which is wider than what they used through 83. From 84 on the power trim/tilt w2as integrated into the mounting bracket instead of having the pump inside the boat and 4 hoses going to the rams. The control cables are universal, but the electrical plug is different. In 1980 the plug on the side of the cowling was removed and the connection was put inside the the cowling behind the face plate support with a different plug.
If I was you and had the 1250, I wouldn't change unless it's getting tired. Sometimes I wish I had the 1250 that I grew up using instead of the 90 (1984) if have now.
