anothe thing to comsider is centering the rear wheels in the fenders. they are about 1 1/2 inches to far foward. you also have to get new spring mounts because the new axle will have wider springs.
This statement has to do with replacing a closed driveline with an open. It has nothing to do with your '56. You can use your stock rearend.
Does anybody know whether it is at all possible to keep my foot starter in doing a 200R4 or 700R4 conversion?
You'll use a later Chevrolet solenoid starter.
the 200r4 is a lighter version of the same transmission and mostly over looked. some say it is not beefy enough but for th straight six would be ok.
If they'll handle a Buick Grand National I imagine they'll handle a 261.
there are some threads in the site about langdons adapters some good and some really don't like it.
One of the complaints about them is they break flywheels easily. The guy doing the loudest complaining was in the hot rod business. I have installed one behind the 248 in my '54 GMC but it is not running yet. I'm hoping by driving it in a proper manner I won't have that problem.
I chose the adapter built by Buffalo Enterprises over the Langdon one because Buffalo's is steel and Langdon's is aluminum.