Van anti-sway bars are different on the front than pickups, so you will need to find one off a van. I know Brandon, 79Big10 had one. He may still have it laying around. As him, or he may chime in here.
The rear, I'm not sure if they're different or not. I've never messed with a van before. I don't even know if vans came with rear anti-sway bars. I'm sure the heavier vans did. If not, you could always buy an aftermarket bar like a Helwig or similar.
Whatever bar you go with, use urethane bushings with it. A new bar will come with urethane bushings. Also, if your van didn't come with a front bar, you will need the brackets which mount to the frame. Brandon bought some for his truck at the dealer. I don't know if there the same for your van though. The dealer will be able to tell you I would think, if someone else here don't know.
It's not hard to install a anti-sway bar by any means. I don't know what your grasp is though.
