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Topic: anyone running 15x8.5 with 4.78" backspacing? (Read 835 times) previous topic - next topic

anyone running 15x8.5 with 4.78" backspacing?

I know 15x8s with 5.5" backspacing works great for welds but I might be able to get some 15x8.5 wheels with 4.78" backspacing? I'm going to be fitting them on a tc rear for my 87 cougar. For tires I'll probably be using 275/50s. Does anyone have this combo or something similar? I want to lower the car and need to know if there will be any clearance issues. Up front I'll be using the standard skinnies.
home ported E7's, HO intake, 93 Tbird cam, 65mm tb, Shorties, dynomax lers, TC 3.73 rear, Mach 1 springs, Bauman shiftkit, epoxy mod, SD, 3G alt, black magic fan

anyone running 15x8.5 with 4.78" backspacing?

Reply #1 –
I had 255/60-15s on 15x8s with 4.5" bs, and they rubbed on anything but flat roads.
Matt
1984 Thunderbird - 89 302 HO, GT40 heads w/ Trick Flow springs, E303 cam, Edelbrock Performer 289 intake and 600 cfm 4bbl, Mustang headers, Jegs o/r H pipe, Dynomax lers, Mustang AOD and shifter, Mustang 8.8 w/ 3.73s, 3G alternator, Mustang front and rear sway bars, KYB 87-88 Turbo Coupe shocks and struts, and 11" front brakes.

1988 Mustang GT - GT40 heads, Explorer intake, 70mm throttle body, 70mm MAF, Crane 1.7 rrs, E303 cam, Kirban Kwik shifter w/ Pro 5.0 deluxe handle, aluminum clutch quadrant and firewall adjuster, o/r h pipe, Dynomax lers, 3G alternator, aluminum radiator, and 3.27 gears.
 
1986 Cougar 5.0, 1989 Mark VII LSC 5 speed, 1980 Mercury Zephyr 4 door (sold)

anyone running 15x8.5 with 4.78" backspacing?

Reply #2 –
I run 15x7's with 245/50/15's with 4 1/8" bs for autox and havent had any problems, but its been close in the front and so I ordered new springs, but it may not help you at all

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick:

anyone running 15x8.5 with 4.78" backspacing?

Reply #3 –
Thanks for the advice guys. Looks like I would have to go with a mustang width axle to fit those kind of wheels. And if I was to do that I might just go one step further with a 5 lug conversion and cragar ss's :hick:  Old school!
home ported E7's, HO intake, 93 Tbird cam, 65mm tb, Shorties, dynomax lers, TC 3.73 rear, Mach 1 springs, Bauman shiftkit, epoxy mod, SD, 3G alt, black magic fan

anyone running 15x8.5 with 4.78" backspacing?

Reply #4 –
I have 275/60/15 on 15x7s in the rear on mine and it only rubs going up to steep of a slant. later this month i can tell you if there is any problems with rubbing with 295/50/15 the i am getting on some 15x10s welds.
84 el camino ss-daily driver(efi mild sbc,2004r, posi 3:42 rear.)
84 mercury cougar v6- was a v6/ nitrous drag car, going back to mostly stock
81 chevy malibu-protouring/  drag car.( efi sbc supercharged 283 that will rev to the moon, 2004r, 4:11 posi rear)

anyone running 15x8.5 with 4.78" backspacing?

Reply #5 –
blackcougar71, what's the backspacing on your 15x7s? My friend is running 275/60/r15s on 15x8s with 5.5" backspacing. It does look close. I would think you have enough clearance to really drop it with the same backspacing. And yes, when you get the 15x10's with 295s I've got to see that! That's gotta look badass.
home ported E7's, HO intake, 93 Tbird cam, 65mm tb, Shorties, dynomax lers, TC 3.73 rear, Mach 1 springs, Bauman shiftkit, epoxy mod, SD, 3G alt, black magic fan