[ QUOTE ]
any advise would be good.
[/ QUOTE ]
It's not a job for the faint of heart. A pickup frame and a chassis cab frame are a bunch different. There are a few outfits that will do it all for you, but they're not cheap. Figure around $5,000 if you have it done with all new parts - including paint to match your truck.
It takes a lot of fabrication to do it "right". For a while, one outfit was selling a DIY kit with everything you needed except the Dooley bed. And that kit cost over $2,000. /ubbthreads/images/graemlins/frown.gif
In the list of upfitters that will add a tow body or pickup bed to a chassis cab (sticky post at the top of this forum), you'll find several upfitters that will do it. Manning is the most popular right now. Centurion has been doing it "forever". And Roll-a-Long has been at it for awhile.
[ QUOTE ]
also i live in NH where or how do i find someone to extend the bed to fit on my 550. would i need 2 beds to extend1? or does someone make etension pieces.
[/ QUOTE ]
The chassis cab cab-to-axle (CA) length is about 3 or 4 inches more than the CA of a pickup. So if you mount the pickup bed where the rear axle will be in the right place, you will have a 3-or-4" gap between the bed and the cab. Most of the upfitters simply add a filler piece between the cab and bed. Some enterprizing folks, including member weweld, cut the right amount out of the middle of the frame, then welded the frame back together. I've never heard of anyone adding a section to the bed to make the bed longer. But I have heard of several upfitters that design and fabricate their own pickup bed instead of using the Ford stock bed. The most famous is Fontaine Classic Traveler.
http://www.fontainemod.com/ClassicTraveler.asp
The frame of a chassis cab also sticks out farther behind the rear axle than a pickup frame does. But that's no big problem - simply chop off the excess frame length at the rear of the frame.