I'm trying to find wider rear tires for my 69 Z. I got 245/60/15s on 7" rallys on the back now but have questions. I cannot find a larger 50 series tire in 15" anymore other than drag radials. I prefer a tire less than 27" tall. So from reading about sectional tire widths from tireracks info page (sectional width increases about .2 for every 1/2" increase of rim width), do you think running the 245s on a 8" rally be a noticable difference?
Sorry, I wasn't clearer. As far as the 245s, I will stay with the 60 series (I like the tires to be around 26ish" tall), but to get anything wider (255,265,275s) I wanted to run 50/55 series so the tire will not get too tall. Is there such a thing as a 55 series tire?
1969 RS Z/28
Last edited by KELVINATOR; Mar 2nd, 10 at 01:30 PM.
Using a tire calculator, a 255/55/15 would be the ideal tire spec for me but unfortunately that tire does not exist. So I'm wondering, if using a 1" wider rim (8" versus 7") will make the 245/60/15 tire "appear" a little wider.
Would a 275/50/15 on a custom 8" rally (4.75 backspacing) fit on the rear of a 69 with no trimming and rubbing? I know guys run 17s and 18s with 275s but how about 15s? I'm concerned about the sidewall bulge. Found a 275 nitto drag radial that has a decent wear rating. A pic would be awesome!
I have the 275/50/15 BFG radial ta on a 8" ralley with 4.5" back spacing. I had to roll the quarter lip, rear of car is up approx 1.5" gap between the tire and the wheel opening when viewed from the side, have approx 7/8" between the sidewall of the tire and the inner wheel tub. I have had a little bit of rubbing on both the inside and outside of the tire but have never damaged the tire. If you don't roll the quarter lip it may cut the tire. The sidewall bulge is too much for my liking, I wish I would have put the 255/60/15 which has an OD of 27".