If your hoist can lift both, pull both. If it can't just pull the engine.
Pulling the engine alone requires you to disconnect everything first. The engine comes out mostly level.
Pulling E/T requires you to disconnect most of the stuff first. The E/T come out tipped back almost vertical. You need to get the front up on blocks to allow for swing room below the truck. Then you need to lift the whole thing skyward to clear the truck. The hood should be off either way, but this way really requires the use of a gantry crane or a really good sized tree limb. The major advantage to doing it this way is time. You save a lot of time disconnecting/connecting the E/T out of the truck because everything is easy to reach and most importantly align. Anyone who has ever pulled them both ways will tell you the tranny and engine are a pain to align when you are on your back under the truck. Combined a SB 350 and a 4L60E is close to 1,000 lbs, if all the pulleys, intake, etc are still on when you pull. A/C if you have it should come off first and get flipped out of the way so you don't have to empty your system. P/S too, especially if you have Hydra-boost brakes, don't want to lose prime. Stopping will be a pain until all the air bleeds out. Alternator and Starter can both come off the save weight and the fan/clutch too. You can easily knock off 100 lbs before the hoist even touches it if you need to. I have access to a 2,000 lb gantry crane and a high ceiling so my BB 454 and 4L80E are coming out together.
I've done many drivetrain pulls on lots of vehicles, but my favorite is the GM H Body. Disconnect a few nuts and hoses, then lift the car in the air while the whole drivetrain sits on the stub-frame under it. LOL. Almost like a built in engine stand.