Nope….I got the right car, just want to add some different wheels is all what’s wrong with that?
It might be a generational thing, but IMPERIALS are about style and elegance, AND being able to easily lose a similar Lincoln or Cadillac in the twisty roads of the world. Might some 15x8, or even some factory 15x7 wheels be better? Certainly. OR maybe some 17x7s with some sticky tires (considering there are some of those tires with the same OD as the OEM tires) as BFG builds in that larger diameters. Even some where the polished rim edge would be about where the older whitewalls might be in relation to the wheel. If you're going to buy new tires and wheels, shopping wisely in wheels and noticing that 17" tires can be cheaper to buy than 15" tires, the larger diameters can be an option that makes financial sense.
All things considered, that car needs all 4 wheels to be the same size and width. Same with tires so you can rotate them if needed. No real need for wider tires on the back, either. Having a "tough looking 4dr hardtop" can happen, but with a car that sits level with all four tires/wheels the same.
The other side of things is that "stance" seems to be more of a "pretender's game" where the car it's on in no way has the performance to match the looks, no matter what. It can accentuate the lines on the 2-drs and convertibles, though, in pre-73 C-bodies with their more-wedge shapes. But that ended with the blunt-front '73 cars. There is ONE exception. A member in here with a '66 NewYorker 4dr with 4 305s on it and a stroker 440 under the hood. Sits level, runs very quick in the 1/4 mile, and still looks like a New Yorker.
As to your wheel choice, better look to ensure they are clear-coated rather than just "polished". If polished, that means you'll have to maintain their polished look. If clear-coated, which is better, some car wash soaps have been known to turn the clear-coat white, by observation. Just an advisory. If the polished surface gets dull, the only way to make it look good again can be "elbow grease, a buffer, polishing compound/wax and money". FWIW
If I were you, rather than invest in tires and wheels (which it does need) first, I'd look to firm-up the suspension with some KYB shocks, add in some HP brake frictions, and learn more about the car and what makes it work as it does or can. There should be holes for up to 4 6x9 speakers in the back deck, I believe. Do not forget the condition of the vinyl top, as the OEMs did not put a full paint job under the top, just primer. With time, moisture accumulates, and rust can happen unseen.
Getting more power out of the 440 can happen, too, but with the 8.2CR, only a complete new engine (even a stroker 440) can really help that. You can re-tune for better throttle response, but that's about it as is. In order to make that 4700 lb car "jump", it will take lots of torque rather than horsepower at 7000rpm. Plus some rear spring upgrades.
Back to wheels . . . I'm not sure of the attraction to the Ansens, but there are other wheel styles out there that can look good on a luxury car. Don't need to spend over $200.00/wheel, usually. A few companies do repro Chrysler Rallye wheels in different diameters and rim widths, which would be "A Family Look" of sorts. VN-501s are another option. REV has some 5-spoke wheels which are shiny and clear-coated, which look similar, if you line shiny aluminum. NO 20s!!
So, get the vinyl top looked at, suspension firmed-up, the brakes improved, the factory radio sent to Aurora Designs/Gary Tayman and upgraded for power, bluetooth, etc. first. Learn about the car and what makes it work. Enjoy it for what it was designed to be. If the car needs tires sooner than later, find some whitewalls for it. Whitewalls will make things look so much better, just by themselves, as they "fit" better than blackwalls.
Then tolerate the current wheels/tires unitl "sales happen" at Summit, every several months. Look around on the Internet (OR even in the "garages" section of this website) for different car/wheel combinations. Even a recent thread on wheels has a Newport 2dr hardtop with different wheels on it. Get a buffer and make that old acrylic enamRe-doing the vinyl roof (and body work underneath, due to ruse) can be expensive.
My apologies if my comments (and those of others above) might not have been what you wanted to hear, but you really do have the wrong car (even if it were a 2dr) for such aftermarket wheels. I understand and laud your enthusiasm for the car, BUT don't try to make it something it was not meant to be or otherwise diminish any value it might have from such.
The first thing to get concerned about spending money on is the vinyl top. That by itself can be very expensive to fix it right. Even if you just remove it, fix any ruse issues, and put paint back on it. Spending money elsewhere, first, will be a costly mistake, from my experiences.
NONE of us are trying to "rain on your desired parade", BUT there are some realities involved of what an Imperial was designed to be and what regular Chryslers were designed to be at each model/trim level. We appreciate your obvious enthusiasm for the car, but perhaps your enthusiasm might be re-directed a bit.
Sorry for the length. Just some thoughts. Enjoy!
CBODY67