gearbox stuck to engine!

trying to seperate my ford d series engine so i can fit a new motor, but it has a capitol gearbox 2;1 ratio on it and the thing wont seperate, i have even stripped the engine down and got the crank of it so i have a crank with a flywheel on it but gearbox still stuck to it, tried lifting crank with endless chain in the air so the gearbox weight mite help it but it still didnt budge, my only next plan that i can think of is to cut some round holes in bellhousing and see whats going on, or try cutting the flywheel up into pieces from the back end and cutting the spline housing of, but the flywheel looks mighty thick!may take a box of cut of discs??
anyone got any ideas, as the engine that is going in it is a 1 to 1 ration paragon box, and the boat is set up for the 2 to 1 ratio?

 

I would cut a hole in the bell housing in front of the flywheel, then use a welding torch to heat the splined collar of the engine coupler plate.

 

If the crankshaft is junk anyway (or if you can protect it with something), I'd whack the forward end of it with a sledge hammer of good proportion. It's likely a shock is all it needs to let go.

 

had a sledge hammer on the end of it all ready, but just dont want to get to butch at this stage yet as i dont want to damage the input bearing/housing of the box, but i think tomorow i will go and try to hire a generator and grind a hole in the housing to see if i can see some kind of plate or something anyway

 

How about cut a small hole in the bellhousing on the gear box side and undo the drive plate bolts so the gearbox will come off and then you can press the input shaft out of the drive plate and or at least work on it.

 

It should be possible to cut a hole and use a long extension with a socket to take the bolts off.