Tires, rims, and brakes

Want to upgrade the wheels and brakes on my 67 cougar.

Couple of things I wanted to do:

  1. Upgrade the wheels to legendary magnum 500 15x7 225/60R15 in the front and 15x8 235 or 245/60R15 in the back

Q: will that cause any tire rubbing or should i get smaller tires? Should I go bigger on the rim size

  1. upgrade the brake calipers to the wilwood 11” with a 6 piston caliper

Q: are the R15 rims inside diameter large enough to fit those breaks? If not, what do you recommend?

Search “tires” here and you’ll see many prior posts with a lot of discussion; this one in particular may be helpful - 69/70 Cougar Styled Steel wheels. What size you running?

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Definitely search this site. There’s a list somewhere that details various experiences. This WCCC video and one of Don’s earlier videos on the topic are a great reference.

The 225 on a 15x7 is a very common upgrade provided the correct offset is used.

225/60R15 in front should not be a problem per the WCCC video. However, Scott Drake center caps used with the Scott Drake Aluminum Legendary Magnum 500 will interfere with the dust caps. The 11" rotors you are referring to are 4 piston not 6. A better fit would be the 4 piston Classic Series. You will still need to get adapter plates for the center caps and modify them to fit with the standard dust caps.

Forgive my ignorance, but the 4.25" “backspace” Don talks about in the video, Can that be effectively measured by laying a straight edge across the back of the rim and measuring the distance to the mounting face?

You’re right, I wanted the 12.19 with 6 piston calipers,
Would they fit on those rims?

Great video! Thanks for sharing. He doesn’t say anything about the rear rims. Do you have any recommendations what to put in the back?

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Search up “Nitto” on this site to find my rear wheel posts. I have a very slight rubbing issue that I will fix this off season. Overall very happy with the wheel & tire combo.

So replying to myself; took the rims off today and see they are marked 15x7 EOT. I believe that would mean 3.5" BS, but measuring to the outside of the rim is 4", hence the “inside” limit would be the measure, approximately 1/2" less, therefore 3.5". At least my best guessing in the matter.

This can be confusing at times. Rim width is the width of the wheel where the tire bead seats. Backspace is from the wheel mounting surface to the inside lip of the wheel(lay a straight edge on top of the wheel with its face down.). So if you have a 7in wide wheel with zero offset , the back space will be 4in to 4.25 depending on wheel mfg and material

Thank you for the clarification; can we deduce that any rim width with a zero offset will have a backspace of about 57%? (57% x 7" = 3.99") So if my 9" rims are ET0 the backspace is likely in the range of 5 1/8"?