Froze Up - How to get Flex plate to turn

[carsnguitars]

So my newest project has been sitting since mid 80's when owner took out underside pan with rocks. I knew the engine might be froze up when I got it.
Pilled the head today, and the sludge mess came pouring out. Cylinder walls caked with rusty gunk and all.

Question - Any thing I can do to get it to turn? Oil, lubicant etc let it sit??
I want to get the engine out, need to diconnect tranny flex plate:
Drop pan, discinnect pistions from crank?

I guess what is best way to get my flex plate disconnected so I can pull it?

Figure someone has been donw this road before, appreciate your insight.

Here is pic btw.

 

[Garys1969RR]

I have seen the engine pulled out with the torque converter still attached to the flex plate. T/C just slides into the splines on the tranny anyway. So just slide it away from the tranny, and lift it out.

 

[67 coronet]

just pull the trans and eng as an assembly.just jack up the rear of the car as high as you can safley get it to give more clearance up front and it will clear.then you can dissassemble at will.i have done it before.

 

[Meep-Meep]

A good home brew penetrating oil is a 50/50 mix of acetone and ATF. Then after it has soaked a bit use a block of wood and a sledge hammer to smack the pistons to free them up.