Wheel fitment Question!

Hello everyone, I am writing because I wanted to see if anyone has done anything similar or knows if my currently picked-out wheel setup would fit or not. My 73 mach 1 fastback q code is currently stock height to my understanding. I am currently looking at some American Racing VN510 wheels (I will provide a link). I am looking to run 18 x 8 in the front and 18 x 10 in the rear. They both have zero offsets, and from what I'm being told by the American racing website, the backspacing for the two in the front is 4.50 and for the two in the back is 5.50. I as well am looking to run 245/40R18 in the front and 275/35R in the rear (If you think I can go larger, let me know!). I believe the front two tires will fit nicely; I am just unsure of the size in the rear and if that backspacing will be an issue. I have seen someone on the forum run 18 x 8 in the rear, but I haven't seen anyone run 18 x 10 in the rear so far, but I will continue to do some looking on the forum and some more research on the fitment. If anyone can help me, that would be much appreciated; thank you very much!

Here is the link if needed:
https://www.americanracing.com/american-racing-vintage-draft

The offset, or lack of, may cause fitment problems. The rule of thumb is half the wheel width plus 1/2 inch, but on wheels that wide rule of thumb is no longer valid.
You can use the spreadsheet in this thread to calculate your clearances, will require careful measurements, especially fender lip inner widths and how well the rear axle is centered between them.
https://7173mustangs.com/threads/tire-sizes.11266/

I have 18x8 and 18x10. You could go wider at the rear. See my post here for details: https://7173mustangs.com/threads/my-new-wheel-and-tire-combo.38697/