Originally Posted by zzpza
I just remove the springs, I haven't had to replace them with anything on the cameras I've done this mod on. I've since used an original Polaroid 100 (Blue Film) pack in one of the cameras without trouble also.
The Polaroid 700 was (if I remember correctly) an instant roll film camera, not a camera that uses type 100 film, which I am more familiar with. However, as long as you are not changing the lens, and you keep the lens to film distant the same, there is no need to change or adjust the rangefinder.
You'll no matter which conversion you plan on doing not be able to retain the same focal plane as it were. You'll need to move the lens infinity stop backwards to compensate. To attain 4x5 coverage (the existing coverage is 3.25 x 4.25, you will have to position the new film plane an inch or so backwards, or open up the film gate and make a new set of bellows to fit.
A place to start would be www.instantoptions.com
Also google (in conjunction with Polaroid conversion), Noah Shwartz, Dean Jones (Razzle, Razzledog), David Harms and Byron.
And by no means look up Littman, Litman (William, Bill or Guilermo - depending on what he decides to call himself). You are bound to come over his rants sooner or later, but try to spare yourself of them (He's evidently patented the process of converting a Pathfinder to 4x5, and defends it verociously, no matter that his idea was at the time of patenting already a 40 year old one.)