my entire swap came out of a car that was hit in the front, motor suspension and all. just make sure if you do go that rout to get under there and check out everything closely. mine just barely got into the radiator and didnt push anything back into the suspension or motor or into the wheels and all the bushings and joints still looked tip top. so to awnser your question it really just depends on how bad it got hit.
After giving my Cragar S/S's away to my dad so he can install them on his '69 F100. I not have a crap set of wheels sitting on my '57. I was at a junk yard and came across a few good Crown Vic candidates to take the full front and rear suspension. I'm looking into making the swap as well.. I mean, I need something to handle the engine under the hood. If there is anyone with some detailed pics.. and some tips/tricks on how to make the Crown Vic suspension work with our '57-'60 trucks MKROG and I will be grateful.
The only difference between doing the '57-'60 trucks vs. a bump (my truck) is the frame above the axle is arched on your trucks. A method of "flattening" that portion is all that is different. The CV crossmember actually sits on 4 small thin pads. All that would be required (although I have seen some pretty in depth mods) is to get the crossmember roughed into position with the mounting bolts in. Make sure your frame is level front to rear. Now draw up your mount bolts maintaining the crossmember at level. When one end contacts the frame you now know what dimension to make the spacer required.
As suggested a search should yield info. There is a '58 going through it right now that is documented. Don't count out the info in the bump area. There really is not that much difference between the trucks on the bottom side and I believe the wealth of information is in that area.
I'm in the finishing stages of this swap right now on my '58. I went a different route than most guys that did this same swap. It may do you good to check it out. I heavily documented it with pictures and text. Plus a lot of guys like elgemcdlf and carcrafter22 did this swap in their 60's trucks.