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Discussion Starter #1 (Edited)
so its the stage of the restoration where i need to order rims and know it will fit! to let you know my suspension i have 2" lowering springs up front and 1.5" drop multi leaf springs hothkins. the car is not tubbed and it has the original 10 bolt rear end. im sticking with the steel rally's

the front i think i know what im going to to: 15x7 4.25 BS with a 215/60/15 tire.

now the rears is where i have my questions! im lookin at the BFG drag radial http://www.bfgoodrichtires.com/specs/g-force-t-a-drag-radial/1161.html 275/50/15 will these fit without issues? or 255/50/16's? the rims i was thinking either: 15x8 with 4.5 BS or 5 BS??

one more question. the car is a daily driver but i choose the Drag Radials because the car will never be driven in the rain so i figured why not get the extra performance for when it goes to the track every once in awhile. but would it really make a difference? or would it be a safer bet to go with the BFG Radial T/A's for the handling? and go with 255/60/15?? http://www.bfgoodrichtires.com/bfg/productIdSubmit.do

any help would be appreciate :D

daniel
 

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I run P235/60R15's w/ 15x7 Chrome Rally's on my 1969 all the way around. In my experience you can get more tire under the front of a 1969 vs a 1967 or 1968 and more tire under the back of a 1967 or 1968 vs a 1969.

A P235/60/R15 has an overall diameter of 26.1 inches. A P215/60R15 is 25.1 inches. If you are going to lower this car 2 inches I would not recommend going anything larger than that on the front end...In most cases the bias ply to radial equivalent on the 14" size GM used was P195/75R14 which was common on GM car's like Camaro's, Regal's, Ventura's and the like back in the day. That P195/75/R14 size has on overall diameter of 25.51 inches. Some cars got P20/75/R14 which has a 26.1" OD which is the same as the plus one size of P235/60R15.

The point is this: The car will be lowered 2 inches The P215/60/R15 should clear up front. The P255/60R15 has on overall diameter of 26.8 inches. If you are going to go w/ these sizes the greater the back space the greater the tire is pushed outward if I recall correctly. Hey it's been 10 1/2 years since I played with tire sizes & wheels for customers so I'm a bit rusty.

Now as far as the 16" size. I would NOT go w/ P255/50/R16. That size was first used back in 1984 on the redesigned all new Corvette. P255/50/R16 was only used until 1989 or 1990 when the Vette went w/ P275/40/17....I would go w/ P245/50/R16 which has an OD of 25.64". That's very close to the P195/75/R14. GM used P245/50/R16 on the IROC-Z in the 1980's and continued the use of that size on 4th Gen Z28's into the 1990's & 2000's. It was also used on Firebird's & Trans Am's. That "245 IROC" size would look cool on a lowered car w/ the right wheels and it's much easier & cheaper to find them than the P255 Corvette 16 inch size. As far as the backspacing on 16" wheels on a first gen? I'm not sure. Not many people were doing that in the 1990's.

I hope this info helps you out. If it was my car I would keep the 15's on it and roll w/ the drag radials w/ a drive train made to run like a bat outta......................
 

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Those 215/60R15's should fit fine up front, but I'd personally consider moving to 225/60R15 just to get a little taller tire (25.6" tall vs 25.2", not a major difference). I'm pretty sure those 225's should fit a '67 fine as well, but you might want to double check.

For the rear, I'd go with 15x8 w/ 4.5" backspace. The 5" backspace would move the wheel inboard more and it might be a bit close to the inner wheelhouse (backspace is the distance from the inside lip of the wheel to the mounting face). The 8" wide on 4.5" BS works fine on a '69, pretty much centers the wheel in the wheel-well. I think the outer fenders are a little tighter on the 67/68, but I'd still be concerned with inner w/w clearance with 5" BS on an 8" wheel.

The 275/50-15 tires might be tight in the back, but the overall size (26.1") seems about right. I'd be tempted to try them as a track tire at least, but I'd be pretty worried about treadwear if you drive the thing much as a daily driver. The drag radials also have a much squishier sidewall, which helps forward bite, but can make the car feel weird in corners. Since I don't do drag racing, I'm not a good judge of whether it's worth it or not.

If you DO go with the Radial T/A's out back instead of the drag radials, you're gonna be stuck with a narrower tire (or a really tall tire). I'd think a 255/60R15 would be a decent compromise.

Tire choices for 16" wheels are pretty slim, so unless you really HAVE to have them, I'd stick with 15's or step up to 17's.

Just my opinions...
 
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