Re: Hello, looking a buying first chrysler,1978 105hp
The 105 was rated at the prop and in later years--1982 it was downrated to 90 HP. The 1978 should be a distributor ignition with an electric eye instead of points. It is a relatively trouble free ignition, however, with a little money and some work you can upgrade to a Prestolite or even Mercury ignition from later Force engines. Although, I really don't know why you would want to do so.
You can change manifolds and install the large TC carbs off a Force 125 and she may put out an honest 100 ponies.
If it is a two piece lower unit, finding props is becoming difficult. These props use a 5/16 inch diameter thrust pin held in place by the tail cone.
HOWEVER: IF the engine has Magna-Power II ignition RUN, don't walk away. Magna power II did not have a distributor and did not have CD boxes mounted on the side of the engine. Everything except the coils was mounted under the flywheel. It was a trouble prone system with a high failure rate.