Tire Size help

I was able to fit a 325/50-15 on a 10"wheel into my lowered 68 Barracuda, with just the .5" offset kit.. Yes I had to pound the inner tubs a bit, to get enough clearance to the sidewalls, all in just one area, and I folded the lip up just a lil. I narrowed my rearend to run a standard 4.5" backspace. As I did that, I centered the housing between the tubs.
For straightline work, I get no rubbing. But around town, I can't act stupid in the turns.
I'm a streeter. Most of the time I'll be in Second gear, which is geared for 3500=41 mph ( Commando 4-speed.)
275s embarrassed me way too often by spinning me out with just a hair too much power; which at that time was around 330hp.
Currently, with about 400 or so hp, and with 295/50-15s on 10s; anything goes. I can go into a turn way too hot, and still come out with the tires on fire; so so much fun. But, as you can see, at 41=3500, I'm on the bottom of the power curve, in the heart of torque. So it's easy with a 750DP carb, to light them up. 325s should be on 11 inch wheels. If you install them on 11s and try to stuff them in the Barracuda tubs, it will not work.
295s on 10s is really a lil too small, but I have learned to run them at 24psi for long tread life, but they do tend to self steer around a lot of sweepers. I learned on the street, to like it. But the oversteer is noticeable enough to where, on a track you might find yourself in the weeds on a regular basis.
With 17s, you'll get more tread for the profile, but still have the oversteer at low tire pressures. So, Ima thinking a 275 on a 9/9.5 might be the way to go, but honestly, I'm guessing.
There is a guy on this Forum, I tried to tag him, but apparently I can't spell @blueAndBlue right cuz it don't work, lol. He'll find you soon enough.
EDIT, see next post. I wasn't even close, lol