My "new" '74 Duster- or why I need a project like a hole in the head

I was able to find the wheels again:
http://www.summitracing.com/parts/mbw-61324/overview/

I saw that someone on Moparts had basically bolted this wheel style right on to a '68 Satellite Wagon, and I've seen them on some other brand-x muscle cars so I think they may actually have a hub center that is the right size. If not, at least they have a bolt-on center cap so opening the inside may not effect anything at all. My car has the 11.75 stock rotors at this point - so based on what you said, it sounds like I may need somewhere around a 10mm spacer in the front. I have the Hotchkis UCAs on the car now.

I know it will probably perform better on a 10" wheel, but at the same time I'm not quite sure I can find wheels that look classic enough in that size and not pay a ton for them. If I actually get into doing SCCA CAM-T autocross I may get another set with some direzzas or something.

Actually those should fit without any hub bore drama. The center bore on those is pretty big and the wheel is thicker than the hub is tall, it will clear just fine. The rims on my Challenger are similar, and same deal, the centerbore cleared the 11.75" rotors fine. The spindle nut should even fit inside the wheel cap. On the lightweight wheels like my RPF1's the wheel is very thin at the hub, so the hub passes completely through and out of the face of the rim, so the wheel cap has to capture part of the hub in addition to the spindle nut.

Yes, if you want to stick with the 11.75" rotors you'll need about 8-10mm of spacer for those, depending on your car and lower ball joint steering stops. The steering stops on my lower ball joints is almost non-existent, so that's part of my rubbing on the frame at full lock.

There are 10" wide wheels out there, the American Racing TT M's come in 18x10 and 5x4.5". In fact, you can get them in both 24mm and 45mm offsets. They're a little more than the MB's but not outrageous. The 24mm offset should fit the front about perfect, the 45mm offset might actually work with 275/35/18's, they'd still leave a smidge more room on the inside than my 295's. Maybe a few mm spacer for leaf clearance. The only thing is that you'd be pretty well stuck with the brakes in the front, most of the aftermarket brakes move the track with out a little, and you'd be pretty much maxed out at a 24mm offset. But if the plan is to stay with the 11.75's they'd be fine.

http://www.summitracing.com/parts/are-105m8165a/overview/

http://www.summitracing.com/parts/are-105m8166a/overview/