What transmission ??

I bet Rob's right. I think the 727 is all they used in 84 Van's with a 360. Here's a picture of a 727 pan. If this is what it looks like it's a 727. Was the van a 1/2 ton, 3/4, or 1 ton? If it was a 1/2 or 3/4 ton it should work fine for you. If it was a 1 ton it might work or might not cause some 1 ton van's and trucks used a bolt on driveshaft instead of a car type slip yoke.