Tire Size
 

I have a stock 70 GTO. I want to put 60 series tires on the stock rims. What size would work best? I was thinking P225 60 14 or P235 60 14. :)

Welcome to the site.:D
Depends on what you mean by "best". Those sizes will work,but are about 2" shorter than say a 225/70/14. You would have to go to a 265 to maintain the same tire height as stock,in a 60 series.
I ended up putting 15" rallys on my 71',many more sizes available in 15" as compared to 14" these days.

Go to 15 inch 2456015 2556015 2756015

I had 235/60/14 on my GT-37 (thats how I bought it) and it's a very short sidewall tire. I have since replaced them with repro GY PG and they look awesome, not to mention fill up the wheel well MUCH better. With a stock 6" wide rim, 235mm or 245mm is about the widest that will fit.

I'd upgrade to 15" if you are set on 235

If you have 6 inch rims you may want to try to find some 7's as the 60 series tires will bulge at the sidewalls if too narrow a rim is used. The wider rims will let the tire sidewalls spread more and let the tread run flatter and more even.

It seems like 265x60/15 on the rears is the most common I seen mentioned. I definitely want a wide tire but don't wanna modify the stock ride height. At some point doesn't increasing width add height to a tire despite keeping the same profile numbers?

P245/60R15 or P255/60R15

my 69 GTO has 255/60/15
I had 235/60/14.....to short, 15's r the way to go.

If you want to keep the 14X6" wheels then I'd say move up to a 70 series tire, 225/70-14.

The 60 series tires that fit a 14" wheel are way too short and don't fill the wheel wells.

The shorter tire will affect your speedometer readings (speed indicated is faster than actual speed, miles will rack up faster than normal) and will increase highway RPMs as well, it changes the effective gear ratio.

This is a 225/70/14. As mentioned, a 60s series is too short for 14" wheels.

Have to agree with slowgto and b-man, if you want to run 14" go with 225/70-14, the size is very close to the original G70-14 and does fit and drive nice.

I took off the 14" Rally II "KU" wheels my GT-37 had and put some 15x7" wheels on with 245/60/15 Goodyear Eagle GTs and it seems they have plenty of room. :)

Tire sizes on my '72
 

I decided to go with 235/60-15 on front and 255/60-15 on rear with my Honeycombs. Engine is out of car so cant exactly judge ride height but If anyone wants a pic or 2 of it lemme know. Thanks.