I tend to agree you are going to be going thru a lot of work with a clip swap and that you would save a bunch of time and labor (and possibly $ by modifying what you have.

I think some of the issues with changing out the front suspension you’re likely to run into include:

Torsion bar location/design. I’m not sure they went to front adjusters, but the early torsion bar cars had rear adjusters and somewhere along the line MOPAR went to front adjusters.

Your mounting points for the sub frame itself, core support, bumper, etc are all going to be different.

Due to the long cover over the steering shaft your steering column in the 60 may be a challenge to hook up.

None of these things are insurmountable, but it will take a good deal of fabrication and re-invention of the wheel, not to mention the time involved.

My own opinion would be to use what you have and upgrade as necessary. The simple way would be to find a 60 donor frame for the V8 frame mounts or simply fabricate new mounts after you cut out the 6 Cyl mounts out.

Besides the mounts you will probably also need the early style BB oil pan which has a bit shorter front sump (it will keep from cramming the engine back into the firewall and creating clearance issues with the linkage heater box etc.

AAJ makes a nice disc brake conversion kit to give you discs up front and if not equipped with PS or a sway bar these can also be retro fitted. Without knowing what transmission you’re going to use (there are no off the shelf automatic OD transmissions for the BB Chryslers) but as I recall the Imperial Club also used to sell a conversion that would allow the original push buttons to operate a 518 (the OD and LU are electrically controlled so that’s the easy part).

While the initial investment for finding and buying the correct conversion parts, from personal experience, buy the time you buy and rebuild the a JY front suspension you’re not going to save any money over the 60 conversion parts and you are still looking at all the conversion work.

Just my 2 cents.