Don’t disconnect the bell housing. Motor and tranny will come out together. Best if front clip is removed to give you access, You’ll have to disconnect the torque tube before you pull the motor & tranny. Then there are 2 bolts under the front of the motor near the radiator and another 2 in the cross member. Lastly, there is a support plate under the tranny tail shaft where the U-joint is and there are 2 bolts there that you’ll have to remove. Disconnect the fuel line from the fuel pump, battery cables, shifter linkages, oil pressure and temperature lines, stomp-starter linkage, and I believe the clutch and brake linkages that are attached to points on the motor. That should be all you’ll need to disconnect.

235’s and others are all nice replacements but come with additional challenges. Others more knowledgeable will advise you.

Edit...... sorry I just re-read your post and you want to leave the tranny in place. I haven’t got experience disconnecting the tranny from a motor that’s being pulled. I will allow others more experienced to advise how to do that.

Chuck
1950 Chevy 1/2 ton (all original)
1951 Chevy 1/2 ton (future streetrod)
1941 Chevy coupe
1938 Chevy coupe streetrod