Actually it shouldn't be too hard to find. I gave one away... Any good junkyard should have one for under $30. Just tell 'em your looking for a C4 bell housing to fit a 250 six cylinder or 302. You are correct, the starter will be down low on a 250. You can also look at the emissions sticker on the drivers side of the valve cover, it should say 250 C.I.D. somewhere on it.
Very nice boat! i have an old 79 seascape with a 350 and a 95 seadoo xp. hope you find the parts. there are some good yards in newark and hayward.
Also, when sending pictures, they have to be 100kb or smaller. Sometimes you can get away with 110-120, but usually it will kick it out. You will love the 302. Even modestly modified with bolt on stuff (intake, heads, headers) you can leave all but the newest fastest cars behind. I can blow a new mustang GT off the road, and I still run my stock rotating assembly with 8.0:1 compression and 59,000 original miles. Even with my stock heads and dual exhaust, the mustang was only beating me by just a carlength or two on the 1/8 track. The Maverick is so light that the 302 barely has to work. You can easily get 20-24 mpg on the highway, especially with those 2.79 gears on the C4. I still get 20 mpg with 3.80 gears and C4, as long as I don't gun it too much. Then I get something like 1 gallon per mile!!! Seriously. EDIT--I re-read the post, and recognized that hardly anyone is discussing the steering aspect of the question. I don't know firsthand, but many on here have swapped from the powersteering to the adapter that AutoKrafters sells, and say it is a "little" hard to steer when sitting still and cranking on the wheel, but barely harder to steer while moving. I tried to take the belt off and see what it felt like, but it was different and much harder, due to the hydraulic system still being hooked up. But, it has been said that once the hydraulics are all removed, it is not bad, if you keep a decent sized steering wheel.
