Best way to take out a slant 6?

I prefer pulling it as once piece. Remove the starter and then you'll have access to the 4 bolts holding the flexplate to the torque converter. Make a mark on the flex plate and the torque converter so you know how to line it up when it goes back on. You'll only be able to see one bolt at a time so after you remove the first one, rotate the engine until the next bolt comes around.

Disconnect the kickdown linkage from the carburetor, that way you don't have to deal with getting it aligned correctly down on the transmission. If you take it off the transmission it'll take some time to get it to shift correctly again.