Paragon transmission binding

Hello, I have 1963 Chris Craft with a 283 and Paragon. The trans seems to be stuck and barely allows the engine to turn by breaker bar. Here are the details:

-This is something that happened to the boat while it was sitting for one year, without anyone modifying or adjusting anything.
-Previous owner started boat with no problem
-Boat sat for one year
-Transmission acts like it is not in neutral
-Shifts from forward to reverse with a clunk but the engine is not free in any shifter position.
-Engine will not crank with starter
- Starter is getting power
-Starter was rebuilt last month
-Engine is very hard to turn with breaker bar.
-Unbolted Trans, engine spins easy
-Bolted trans on, engine is bound up again.
-With shifter off of transmission, engine is still tight.
- prop is not bolted on to trans.

Im a mechanic, but not familiar with the paragon. Please advise on things to try or steps to free the transmission up.

thanks, Ken

remove the remote cable and shift the gear into neutral...if the gear is still binding, send the gear out to get it rebuilt...or order a kit and have at it...

Thanks

Welcome to the forum. Must have got moisture in it. Will have to be dismantled and inspected. They are not that complicated, but they have to be kept clean and dry....not stored with moisture. I rebuilt one of these 327 250 hp w/Paragon. Absolutely incredible boat. Sound and performance undescribable. I'll never forget my test drive after the overhaul. The Paragon was not difficult to overhaul, and handled the hopped up 327's 300 plus horsepower like a dream. I believe they made about 70 with the 327 and 100 boats with a 307, both steel crankshafts driven off the harmonic end.