Ok so my 55 came with American Racing Wheels 15"x8"x4" BS and I am trying to put the widest tire I can on the rear, the car has the stock rear on it I am thinking a 255/60R15 will work ?
Ok so my 55 came with American Racing Wheels 15"x8"x4" BS and I am trying to put the widest tire I can on the rear, the car has the stock rear on it I am thinking a 255/60R15 will work ?
That is the size tire I have on my "55 only I have 4 1/2" back space on they fit fine.
If the rearend is stock it's about 60" wide at the wheel mounting surfaces. An 8" wheel with 4" of backspacing has a -1/2" offset so it moves the center of the tire outboard. That makes the tire track about 61". A 255 is about 10" wide so the outside of the tires would be at 71". Most of these cars are 71 1/2 to 72" across the wheelwell lips so that would be pretty tight but tires should fit if everything is centered. A little more backspacing would be better.
56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
Thanks so much for the replies, going to measure the rear tomorrow and make sure everything is set to stock and go from their.
My newly acquired dream is a '56 Bel Air 4 door hardtop. The factory tire size is 670-15. Does anyone know if the G78-15's (one size up) work with no fitment issues? Thanks!
What's "crappy" about metric sizing? It gives you a lot more information about the tire than the old size designations. 6.70/15 is pretty meaningless when you're trying to fit a tire. All you know is the tread width and wheel size.....you have no idea what the overall width. sidewall height, or diameter is. Metric sizing allows you to determine those parameters with a little simple math. Even the old letter designation of "G", "H", etc. was pretty lame.
Last edited by chevynut; 02-28-2019 at 07:45 AM.
56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
''One size up' works on almost any car, but I'm betting a G78 won't fit in your spare tire well?? Would be interested to know for sure if you buy that size.
PS. Not sure where you're finding G78's new, but most new tire stores will mount/try a different size for their customers, and won't charge you if you find out you need a different size...? Ask them!
Last edited by BamaNomad; 02-28-2019 at 07:51 PM.
I decided to go with the OEM size 670R15's from Coker Tire. They have the original look (2-3/4" whitewall with the bias tread) but with underlying steel radial construction. My car is relatively original so although the 670-15's have that "skinny" look....that look is what was coming out of the factory in 1956.
I use a 205/75/15 for a spare in my 56, tires in ground BFG 225/70/15. Closer to right than doughnuts on new cars.