Looking at your photos, looks like 1 piece cyl head. beware of core plugs in head, they pop out, use plate strips between cyl head bolts to hold them in. watch cyl head bolts (2 washers on each bolt) you can take 1 washer off on bolts you use the core plug plates on. Original bolts was too long !!!. If you deck head check bolt length again. Only use gen Yam head gasket !!.
You can see pistons if you take exh side plate off. 6J2 have 2 thin rings, 6H3 have 2 or 3 thicker rings.
If it has black carbon reads, that was standard for 70ces, check they seat well and no frey on edges, common problem, boyson reads fit, from memory slight mod to suzuki 185 cc reads fit !!!
Rings only jam cos of poor quality of batch of 6j2 pistons, land breaks away near exh port.
Check stat, most have been removed, I think its best if only part removed, leaving a choke in waterway.
How is engine getting water, do you have pick up on bullet ?
Lots had pickups on sponsons feeding into drilled out flush holes on gearbox with original gearbox holes blocked.
11x22 is too big !!!
Looks like engine is flat on transom ?. good starting point for engine height is to have lower gearbox oil plug level with bottom of sponsons, then work from there ?.
Boat looks like old Baracuda ????? prob late eights at guess (no cell).
I would cut the trim tab flush with bottom of cav plate and add a little to skeg
and put steering back to one to one !! and move steering arms to the tiller arm under the engine tray. With the steering arms on powerhead bolts, engine can come loose, also can break mid section ( mid sections are like rocking horse sh*t to find)
Depending on what you want to use it for, lots more you can do !!!!!!!!!!!!!!!!!!!!!