I've always used an 8x10 ciba drum for developing 4x5 and 8x10 B&W film. For 4x5, I put two sheets in the bottom, emulsion facing inward. The sheets have the 5" side against the end cap of the tube, and I'll put 2 sheets end to end, so the 4" sides are opposed against each other.
Originally Posted by fil
I do seperate the sheets a bit, so there is a gap of about 1" between the ends of the sheets. I then process with 75 ml of chemistry for each step, do a few passes of water at the end as a primary wash, then pull the sheets out and tray wash them.
I've never had a problem with any anti halation layers not coming off, or the film moving around.
I've have had problems trying to do 4 - 4x5 sheets at a time, the film will overlap then, but to a surprisingly small degree.