Re: Where do i find the HP rating?
OK, I found what you need:
Go to this site:
http://www.chryslercrew.com/
Scroll down on the page until you see the link for factory brochures, click that, then click 1975.
From what I can see, the 16' bowrider was rated for 100 hp, so you should be OK, as long as your transom's sound. But check the brochures. The type's kinda small, but you can read the tables if you push it.
There's something for everyone on the web, it seems...even owners of 32 year old Chrysler boats.
You asked about bracing the transom. Is yours not solid? If it's not, then you have to fix it, if you're going to avoid a disaster.