I've noticed this is a somewhat common conversion and was wondering what it takes to do it? My guess is that you swap on 2dr doors and move the pillar/post forward to match them?? I'm thinking of building an altered wheel base car and thought this might be a good route to go? Any insight into this would be appreciated.

John Kunkel here on the board has done it with a wagon.

There's other conversions on the web if you look hard enough.

Looks to be pretty simple and straightforward.

If you look at the rear seat area of a 2-door with the door panel removed you'll see the 4-door opening is there with a panel covering it. It seems that all early B's were built as 4-doors and the B pillar was moved back for 2-doors and the rear door opening covered.

The link below is to my photo album showing the conversion on a wagon, same for a sedan or hardtop:

http://good-times.webshots.com/album/563441250xftUsu

The only problem with making a 4dr sedan into a 2dr is good parts .If you have good doors,good quarter panels and everything else required you probably have a good 2dr to start with.Also,it is time consuming and a lot of work.And,you are working on two cars instead of one.There is a 64 Dodge about 15mi from me that was started 2yrs ago.So far,driver side is about 3/4th finished,passenger side still to be done.

You are looking at about 80-120 hours of work to do correctly. Need doors, and quarter panel, post, inner door structure, lots of spot weld cutters! You have to take two cars apart. Many more hours for the AWB work.

I have a '65 Coronet 4door-into-2-door sedan conversion in progress, whith some AWB mixed in for good measure. Already had a fair donor; a '65 Coronet convertible that was a real gawd-awful mess and useless for anything other than a donor. I cut the quarters off, took the doors, and then found a 4door sedan later and started on it. It's all here: www.primerking.com
Most important thing to remember is this: if it isn't square/flat/level/straight when you start, it simply cannot be when you're done. Measure 3 times and brace everything before you start cutting and continously check everything in the process. You can't be too careful. If something gets crooked in the process, it'll be painfully obvious when you're done.