"It's a 1966, made by Chry
"It's a 1966, made by Chrysler. It should say 9.2 hp on it.
Does it have the funny top with the electric starter over the flywheel?
I have a couple of 1966, 6hp Sea Kings and have been able to get parts by taking the parts manual to my local marina and going through the Sierra catalog to match. I got waterpump and lower unit seal parts.
Be very careful when shifting -- those years of motor have a gearcase casting weakness. Shift at the lowest speed possible, with a smart snap, not a slow ease-in. Shifting into reverse at high rpms often breaks the area around the rear bearing retainer ring.
I have the service and parts manuals if you need."