Leon2982,
I'm no expert, so you can take this for what it maybe worth...
If it were me, unless you've got the front clip off, I would pull the 216 block and bell-housing, leaving the tranny in place. It's alot less to disconnet and pull out of there and you don't have to worry about disconnecting your driveline, as messing around with the driveshaft bell and those u-joints tends to be a pain in the butt. Very little space to work for those of us with fat fingers.
You can still change the clutch and pressure plate. On the back of the 235, you'll need to line-up the new clutch and pressure plate with an alignment tool, bolt it all in place and stab the 235 back onto the tranny.
This really isn't difficult. If it don't line up exactly, you can always turn the motor a bit by hand to make the splines line up.
The linkage etc. should all be the same, since you're not changing tranny's.
As for the motor mounts, I believe the 235 has side mounts. You'll either need to fabricate something to use them, or drill out the bottom of the plate behind the harmonic balancer to use your old front mount.
I believe the only other issue you'll have to contend with is the clearance of your water pump. I think you'll have to either get a short-shaft water pump or purchase a water pump adaptor.
I'm probably overlooking something but I'm sure someone else will chime in and remind me.
Good luck.
