Why bother will all the calculations?

Plug and chug. :tup: (Plug in your stock setup on the left, plug in your new setup on the right. Play with the widths and aspect ratios on the right and see how they compare to the original setup (left).)

Wheel / tire size calculator / comparer - WWW.RIMSNTIRES.COM

It's not just the diameter any professional will tell you that you shouldn't put a tire that's too wide for the wheel. It can cause premature wear and tire failure.

Dang, Just learned a lot about tire fitment. thanks for asking the question

Very true, I have seen 315 on 9" wide wheels, and be fine, but we have such a smaller side profile it makes putting wider tires on stock wheels harder. I do not think 305 will cause any issues though, if I had to go from 35 (275) to 20 then maybe, but going from 35 (275) to 30 (305) should be fine.

Tru well I wanted to find out the most common fitment of tire that people go with but I guess there is none everyone runs a bunch of different crazy setups haha.

How are these 5zigen pro racer forged lugs.. Or is there somethig else you guys recommend that's lighter and not 3x the price haha.
5 Zigen ProRacer Forged Racing Lug Nuts: Evasive Motorsports | PH: 626.336.3400 Mon-Fri, 9am-6pm PST

I think on stock wheels 295 in the rear is probably best, but the V12 do not come in a size I like so I am just jumping to 305. On 10.5" wheels you should be on 295 or 305 (and I would suggest 305), both for looks and fitment.
Lugs I am not sure of.