there was a guy who did a crown vic/marquis front end on his 55-59 but I can't seem to find it. he made brackets for the frame and bolted it on. it was kinda backyard/messy looking but it worked apparently. check what year crown vic you need because the track width changed somewhere in the early 2000's I think.
lots of guys weld in a camaro or nova clip. some do a mustangII cross member, some do a complete frame swap from another vehicle. you will likely want to swap out the rear axle due to the gear ratio, depending on what your purpose will be in the end. some guys use a camaro rear, some guys have used the ford 8.8 from explorer but the pumkin is offset to one side. mustang has an 8,8 that is centered. it kinda all depends on what you want for an end result. a little more info there would us help I guess. I think before you spend money on the frame you should do a frame check to see if it is square, not sagged out and check the integrity of the rivets etc. the assy manual has all the frame dimensions and you will see it is a pretty straight forward design so some have built their own frame from rect tubing with components from newer vehicles for suspension. some guys have used corvette parts for this. here is a link to a build like this with a custom frame etc but lots of others have done the same with their stock frames.
https://67-72chevytrucks.com/vboard/...d.php?t=766016
some guys will install a clip out front, then cut the frame off behind the cab and install a 4 link or some other suspension that requires a big C notch. really, by the time it is done, you are left with about 4 ft of original frame under the cab and the rest is welded together. maybe the new frame idea isn't that much of a stretch then?
on a build i have I stripped the frame completely so I had 2 rails left. sandblasted, welded the not required holes shut along their lengths, boxed it in, installed a MII front end, a 4 link out back wit an 8.8, built cross members, motor and trans mounts etc etc. then I scrapped it and went with an envoy frame, floor pan and firewall. they come with 4 wheel discs, ifs strut susp up front, rack and pinion, 4 link rear with coils or stock air bags, fuel tank etc, aluminum block LS engine, O/D trans, etc etc. it is a LOT of work though. in comparison, it is a lot of work both ways but using the stock frame is easier if your fab skills and tools are limited. on mine the truck was really rough and needed a floor, firewall, etc so I used the envoy parts. dash mounted brakes come with the firewall.
here are some links to some good info to have when figuring out your build components compared to your final intentions
here is a link talking about the same thing and it has a few dimensions
https://www.hotrodders.com/threads/5...estion.316114/
another link talking about swaps
https://www.trifive.com/threads/crow...nt-end.108328/
you are gonna want to download this for future reference. it has original frame and body
dimensions as well as where spot welds are, how things fit together etc etc
https://www.trifive.com/d1/55-59Assy.pdf
another good site for info
http://chevy.oldcarmanualproject.com...esto/index.htm
another good source if considering a frame swap or clip
https://www.gmupfitter.com/body-builder-manuals/
a great wheel/tore size site for tire size comparison, sizes etc
https://tiresize.com/comparison/
a site for tire size-gear ratio-trans-and final rpm
https://www.randysworldwide.com/calculators/tire-height
a site with calculator to see your wheel offset and how it affects the steering geometry with a different tire size or wheel offset
https://www.wheel-size.com/calc/?whe...cl=50mm&sr=0mm
another rpm =rear ratio calculator
http://www.csgnetwork.com/multirpmcalc.html
how about a list of what you want it to be like when done. canyon carver, grocery getter, weekend cruiser in town, highway tripper, trailer queen.....