Re: Adding power trim
As long as the steering yoke has the upper holes to mount the upper bar, which holds the tilt cylinder and the shock absorber, then yes, stock power trim/tilt can be added. However, if you have the smaller transom clamps without the one inch holes for a steering tube, you might also want to replace them too.
You can use almost any power TNT from Chrysler 3 and 4 cylinder engines and Force 85, 90, 120, 125, and 150 before around 1994. 94 on, used a different Mercury style TNT which will not adapt. If ion doubt, ask if the for sale unit has 5 bolts on a pentagon shaped trim cylinder. This is the one that will fit.
Think long and hard about doing this: The power will cost somewhere around 400 bucks and you are putting it on a 300 dollar engine. Unless the engine runs VERY well, you simply may be better off buying a newer engine with TNT already on it.
While most parts are similar to newer engines, propellers are 18 spline thrust pin drive. They are becoming more difficult to find. An engine newer than 1979 will have the much better one piece lower unit with a larger selection of props and better performance because of the better ignition system and lower unit. The hood latching system is also simpler and better.