6inarow,
You may find that it will work better with it hooked up. At least I did on my '66 Chevelle.
Zeke,
I run the F298 in a 1960 261 with an 848 head, and I wouldn't recommend it be used with an automatic unless you "loosen up" the converter. Find out who all the local streetrodders take there trannies to, and talk to them about your proposed setup. They should tell you the same thing. The 200-4R would work out much better because of its shorter first gear and with the overdrive it will allow you more flexability with rearend gear selection. Basically you get a good launch and still cruise down the interstate.
The '56 has a in drive idle speed of 425. You would need to nearly double that with this camshaft, which means the engine would be racing when in park. I have been around a few overcammed automatics before, and it is not a fun driving experience.
Thats 600 in drive, not 800. I doubt that the converters in question are going to be identical. Apples and oranges...