I have 5 stands all in use all the time

Generic 2000# 4 wheel unit I use for diesels, BBs and smaller

Generic 3 wheel pice of junk I only use for V6s and 4 cyls

AC Delco 1000# 4 wheel on I shaped lower that is pretty nice, I will use it for an ocasional BB but mostly SBs

Central machine and an evercraft seem like the same things that I use for SBs and smaller. The both have the I shaped lower.

If your gonna do BB engines frequently get one with 4 wheels on 2 legs not the I shaped ones. My big 2 leg unit is real nice, it don't even flex when you set a fully dressed cummins on it and still rotates easy enough if you adjust it low enough center of gravity when you bolt it on. Some of my other stands it is hard to get them low enough you can still flip it upright with the heads on. The big one is no big deal and since it is more stable I can use a big cheater bar to flip it when it gets top heavy and not worry about the stand falling over.