Lexus SC300/SC400 front suspension
The track width difference isn't a 2-door to 4-door thing. It's a '67-'72 drums or KH disks compared to '73+ disks thing. From a factory TSB...
You're probably correct. I was just pointing out what the 1972 Plymouth service manual stated. It doesn't point out a difference between disc or drums just 2 vs 4 door. Go figure.
A few other thoughts. Our A-body's are NOT best served by zero offset front rims. Even most of the factory rims have a +6 offset, not zero. If you want much wider than factory width tires, well, the 18x9's on my Duster are +27 and that's with the '73+ width. So, adding a few inches is a big deal, if you go past +50 for a wheel offset you're going to have a hard time finding rims. And what's the point of adding an allegedly better handling suspension if you can't match it up with a set of giant front tires to actually keep the whole mess on the ground?
Our A-body's may not be a true zero offset but, for most practical purposes, they are considered as such. I know that doesn't mean squat in a technical discussion but it's just how they have been looked at over the decades and rims have been used accordingly. I know as long as you don't deviate too much from the factory track width with the rim/tire combo it shouldn't affect the scrub radius too drastically and the negative handling effects that come with it.
Finding rims to work is not an issue for the Lexus or CV front. There are literally a few hundred styles/sizes available to fit. The real issue is getting a rim that will also work on the rear that matches the front high offset without using a longer rear axle, spacers, custom built rims, or some combination of the three. Of course, going with off the shelf classically styled muscle car rims is practically not an option.
I'm not against hot rodding or anything, I've done my share. But just because the SC400 is a good set up doesn't mean it will still work well when it's been modified to fit an A-body, or that an A-body will work well with SC400 suspension. There's a whole lot of engineering that went into both, and if you want to put them together and still have it work well it will take a whole lot more.
Possibly correct but no one will ever know unless someone tries it. It could be great or it could suck. I know there are a lot of things that need to be considered such as the ride height, track width, the angle (if any) of how the cradle was mounted in it's OEM vehicle, possible strengthening/clearancing of the chassis, engine mounts, connecting the factory column to the Lexus or CV front end, etc., etc. However, that's what hot rodding has been about since it started, trial an error. Seems like most people nowadays just wants to buy bolt-ons and doesn't want to, or doesn't have the skills, to research things and fabricate/modify things themselves. <sigh>