Wanting a 18x9f 18x10r wheel setup am I crazy?

Nice job Emil! :D Your specs are exactly in line with my findings. Since I don't have a mini tub I'm 18 x 9 all around. Backspacing up front comes in at 6.4". As long as you use the narrow Hotchkiss front sway bar or the pro touring specific Hellwig bar, there are no rub issues. The rears are 6.0 BS and fit with the .75" spring relo kit and a factory 71 A body 8.75 axle. What are your height numbers to your front and rear fender lips through the centerline of the wheels?
Thanks Peter, I like how yours is setup too and I bet it really sticks! My front is 25.5" to front fender lip, rear I havent measured but its pretty low with a full tank, I would imagine pretty close to where yours is.

Very cool. I wonder if I could fit a 275/40/17 in the front of my 68 fastback on a 17x9 inch wheel? I have the 73 up disc brake. Currently using a 17x8 with 5.72 backspace and a 3/8" spacer with 245/45/17's....
The problem you may encounter is upper ball joint/tierod contact with 17s. AutoXcuda Steve would be the guy to ask about 17s on a B-cuda since they do have different wheel openings than the Darts/Demons do. I just went for it after a couple of pulls of the tape and got lucky that it worked out.