The swap isn't bad, but you will need the inner mounting tabs for the buckets.
There is a bracket (pictured on Jeff's site) that the front inside of the seat mounts to. Non-bucket trucks do not have these. After failing to make a decent set (I tried!), I went to the salvage yard and cut out two from a Suburban. Brought them home, cleaned them up (ground down the cut outs), welded in, painted and mounted the seats.
Here's some pics from my build where I did this part:
http://67-72chevytrucks.com/vboard/s...=327474&page=4
It's not hard to do, just make sure you get those mounting tabs. You will have to drill a hole in the back, for one of the back bolts to go through as well.
Room saved. I have the low back buckets, but I did notice more room than with the bench. I'm 5'8 225lbs, a lot of mountains with some snow on them from the years. With bench and stock steering wheel, it was a little claustrophobic, but with the buckets and a 14.5 steering wheel, I now have to move the seat forward about two inches to get it where I like it, so I did see some additional room.