My dad had an inboard boat when I was a kid and it was always stranding us. One day it caught fire so he finally sold it. I didn't think they made them anymore. Because of that I promised myself never to own a boat. "A hole in the water to pour money into." As such, I have very little knowledge of them.
Why would the engine need to run backwards? Can't they make propellers that spin in the opposite direction?
I see that you have a wood frame that spreads the weight of the engine along the hull. I can see a protruding knot in the upper edge. You might need to replace that. I'd suggest using a better quality lumber.
Boats certainly are a money pit, but so are project cars and we love them all!!
Correct Craft designed the boat with an RR engine for a few different reasons. Yes you can buy props for either rotation, and even my transmission would allow that. I've heard of undesired handling characteristics of these boats that have been converted to standard rotation, so I would like to keep it that way, even if it is a PITA.
You are right, the wood frame (called stringers) are completely rotten on this boat. I've done a few stringer reconstructions and will need to do this one. When new, and once complete, the wood is completely encapsulated in fiberglass. This boat sat with water in it, which crept into the cavities and rotted the wood substructure. Some people use newer composites instead of wood. I say if wood lasted 40 years, with better fiberglassing techniques I can get at least that out of it.
I can buy marine long/short blocks but I am always weary of other shops work and some of them don't have great stories to tell online. That may be the way I have to go. I would prefer to build myself, but may not have that option if I can find a rebuildable core. The marine specific items are easy to swap over to any long block, and the long block is identical and interchangeable for marine/auto except for camshaft and in some cases, head gasket. Heads, valves, pistons, bearings etc are all shared across platforms. There is not much benefit to an automotive block, except availability. Finding a 302 marine rebuildable core is not easy, but finding a mustang motor is a dime a dozen and it is easy to swap over any marine specific parts to that block. The tricky part is the reverse rotation. To run a 1 piece rear main 5.0 block in reverse (with the marine cam and dizzy) I need a rear main seal that is NLA, as they are directional. The older 2 piece blocks (like the one I have) use a 2 piece seal that is available.
I have also found locally a 351 marine engine for decent money. It is supposedly a fresh rebuild, which is unfortunate, but I'll take what I can get. At least with a marine engine I wont have to change the core plugs and drains but I'll still have to swap over all my accessories and exhaust manifolds. (it comes with an intake mani)