Custom 300 tires and wheels

[GregV]

I want to go with a 15x10 torque thrust with 295-50-15 in the back and 195-55-15 7" rim maybe 6. Has anyone tried this combo? Greg

[lalessi1]

There is no way to make that wheel/tire combo work on the rear without serious mods. I have 235/70 x 15 on 7" rims with 4.25 back spacing now (front and rear). I am carefully looking at 275/60 x 15 on 8" rims with 5.25" BS. It is VERY tight maybe 1/2" clearance to the springs and 1/2" to the trimmed quarter panel lips. Have not "pulled the trigger" on the upgrade yet. This has been addressed numerous times on this forum, you might try the search feature for more help on that topic.

[RICH MUISE]

Ditto what Lynn said. I also have 235-70-15's on a 7" rim in the back. When I wear these out, I'll jump to 255's. I have narrowed my rear rend 3/4 per side, which is about as far as you can go without running into the springs. I also have shocks that let the rear drop further for tire changes, and disc brakes which are easier to get a wheel over than a drum. Can't remember my backspacing off hand, but it may be the same as Lynn's.
Guys have done what you're  thinking about, but wheel tubing, spring relocation, wheel well flange trimming, differential shortening, and some have done frame mods as well. May require special custom made wheels for the backspacing you'll need.
You must have some serious horsepower to want a 10" rim in the back. JFYI, the 235's we're running are a stout 9 1/4" wide. 255's will get it over 10". Almost none of the manufacturers make an 8" wheel with the correct backspacing for our needs.

[GregV]

I will have about 500hp and about the same it torque, that is why I wanted a wide street tire. I am also running Caltracs 1" in back and 1.125 swaybar in front. Also doing rack and pinion and Wilwood disc braked alll the way around. I was thinking of 265-50-16 might fit better, not as wide.

[GregV]

oop's 255-50-16

[gasman826]

A 10" section width is about the max.  This yields about the 1/2" minimum clearance per side.  This also varies vehicle to vehicle depending on lip trimming, body to frame relationship, ride height, etc.  I have 255x55 front and rear without rub.  But you know what they say 'if they ain't rubbin'...they ain't big enough!!'.