Hello,
I have been looking and looking for the right tire size for my 70 cutlass supreme and I have narrowed it down to a Nitto G2 245/45/r18 with an American AR605 Torq Thrust M 18x8 with a 4.5" backspace with a 0 offset for the front and a Nitto G2 255/45/r18 with an American AR605 Torq Thrust M 18x9 with a 5.94" backspace with a 24mm offset. My question to everyone that's able to help me understand tires is if this is a good setup to go with to fill in these fenders on this car and for running stock setup with a disk brake conversion. Want the most rubber on the road without having to rub or roll my lips in the back, the fronts say they would be 26.7" tall by 9.6" wide and the rears would be 27" tall and 10" wide. Any help would be much appreciated.
Thanks,
Mauch712

 

Those are excellent choices. I think you'll be very happy with the results. Your 255/45-18s are virtually identical in overall size to the 255/60-15s commonly used on these cars.

 

Thanks for replying Joe, I appreciate the feed back!!!

 

Those are close to stock height so your speedometer should be close. My 10" wide rims fit with ease, I believe 4.5" back spacing. That leaves an inch between the frame and rim lots of room from the lip as well.

 

Mauch:
70-72 Olds A-bodys have lots of wheel well clearance in the rear. I have 285/40R18s on 18x9 rims with 5.25" backspace: I have about 1-1/2" clearance inside between the tire and frame and about 1-1/4" clearance on the outside between the tire and fender lip. According to the Tire Rack website these tires have a section width of 11.4" and are 27" tall.
Here's some pics from my project.