any 67-68 mustang or cougar guys running a 275 on an 18" rim in the rear

[67cougnut]

im looking to go to 18's was just curious if there was anyone running an 18 on the back of a 67 or 68 with a 275 tire i wanted to get some dimensions if your willing to share. I have been told i can get a 18x9-1/2 on the back with a 275 tire and i have the measuring tool just cant do anything with it till im better so i thought id do some research first and yes i have already rolled the wheel well lips.-thanks!

[rayy]

You should be fine with a 5.5" backspacing in the rear. I have run that on a 67 and a 69 Mustang with no problems at all.

[kmcanally]

I run and 18x9 with a 275 tire on my 68 coupe.

[67cougnut]

what back spacing are you running?

[67cougnut]

You should be fine with a 5.5" backspacing in the rear. I have run that on a 67 and a 69 Mustang with no problems at all.

thanks!

[kmcanally]

These are 94-04 Mustang wheels in the back with 5.9" backspacing and no spacers.

[67cougnut]

These are 94-04 Mustang wheels in the back with 5.9" backspacing and no spacers.

Thanks!

[67cougnut]

These are 94-04 Mustang wheels in the back with 5.9" backspacing and no spacers.

little off topic but what did you do or use to achieve the ride height on the rear of your coupe?

[1bad68cat]

I don't know if it helps, but I run a 17X9.5 TTII w/ a 285/40 Goodyear tire. There is slight rubbing if I enter a driveway with a steep incline and at an angle. The back spacing on the rim if 5.75

[kmcanally]

little off topic but what did you do or use to achieve the ride height on the rear of your coupe?

They are Global West Leaf Springs that I had de-arched 2"

[67cougnut]

They are Global West Leaf Springs that I had de-arched 2"

so you had them de arched for an additional 2" or total of 2"? also is it pretty safe to say that if i need my car to be 2" lower i get the spring de-arched 2"? or is it like coil springs where if you want to lower it 2" you take half of that out of the total spring height? thanks again! almost forgot did you have someone local de-arch them? or was global west able to handle that for you?

[kmcanally]

I de-arched them an additional 2"...I do not know how much drop is already built in to the GW leafs. When I built my car I mocked up the ride height with 2" blocks and then took them to a local spring shop to have them de-arched that amount.

[67cougnut]

thanks for the info. i need to lower the back of my car quite a bit and i have new mid eye 4-1/2 leafs in the back so id like to de arch mine if possible.

[robertjra]

have you seen gears on tv he is doing a sweet cougar with a torque arm and a 700hp big bolck he is running a 275 on a 17"

[1red68]

what tire are you planning on running on that wheel? i have noticed that section width verys some by mfg. I was looking at some Cooper Zeon RS3 with section width 11.12 while Nito NT555 are listed as 10.91....both are 275-40-18. i guess my ? is, just how tight is it back there???

i'm planning/hopeing to put my 68 back under the chopping block next winter and was thinking of 18's also so you have my attn:
& i never thought of de-arching the springs... likeing that idea too......

[Angelo]

Hi, I wanted to let you know that although its snug, its possible to run even a 295 on a 18x9.5 rim if your willing to use a spacer to make it work. You are going to have to run a sway bar in order to eleminate any chance of rubbing. It made the difference on my 68 coupe. No rubbing and i still run leaf springs.