1968 Firebird Wheel fitment Question

[tcolsh]

I have a 68 Firebird stock suspension set up, lowered 2 inches. I found a set of wheels I like but not sure they will fit.

I plan to run tire size - 245/40/18's up front and 275/40/18's in the back
I am looking at a set of 18 inch wheels but the only sizes available are the following
Front - 18x8.5 bs - 5.125 / Rear - 18x9.5 in bs - 5.25 or 5.75

Can anyone tell me if these will fit.

Thanks for any help you can provide...

Tom

[Z06vet]

The 5.75 BS on the rears should work fine. I'd like to see closer to 5.5" BS on the front, but it somewhat depends on the brakes youre running and alignment specs. Your tire sizes are good, but i do prefer the 275/35/18 over the 40 series- only from a looks standpoint.

[tcolsh]

Unfortunately that is the only size offered in this style wheel. I am running disc brakes up front, not sure the type although it doesn't seem to be anything modern. Probably a standard disk brake upgrade... I wouldn't mind seeing the 35 series on that combo....

Thanks for the info!

[williecutlass]

I just put that same tire and rim size combo on my cutlass.

[tcolsh]

Hoping someone with a Camaro or Firebird can confirm the same!! Did you go with 40's or 35's?

[Dark Pursuit]

I had to change the front wheels that I ordered with a 5.5 offset as it brought the front wheels in way too far. changed to 4.5 offset to bring the tires back out to match body lines . I have 18 in front and rear 18x8 with 4.5 offset front and 18x9.5 with 5.5 offset rear. Firebird rear axle should be about 1/2 inch wider than camaro, so 5.75 should center your rear wheels in the wheel well very nicely.

[Z06vet]

The backspacing he listed is for an 8.5" wheel, not an 8". The 5.125 should be ok, but like I mentioned before if the brakes he's using push the wheel out (as many aftermarket and even factory stock style disc conversions do) it may be a bit tight. I have even seen variances in rotor hub dimensions on several first gen cars. A little neg camber can help you gain a bit of clearance between the tire & top of the wheelwell, if needed. There are also shallow rotors available that will bring the wheel in some if needed. There are so many factors that come into play on front wheel backspacing. Just remember you can always move the wheel out, but you cant move it in..

[68Formula]

I think you're fine. I prefer the 40s on the back since the rear arches have a little bigger radius, it appears more proportional compared to the front.

[Wall]

I have seen some 67/68 Firebird guys run 275's on the rear but they don't fit on mine. I bought a set of 18x9.5s with BFG 275/40/18's and I can push them into the factory wheel well but it touches on the inside and outside, no room on either side to spare. Maybe the BFG's are a little wider than other 275's or maybe my car has a little less room than others but just make sure you take lots of measurements before you buy.

I went ahead and bought DSE mini tubs for my car since I wanted to run a wider wheel and tire eventually anyway. I could have possibly massaged the wheel wells and trimmed enough to fit the 275 but it just gave me a reason to mini tub it.

[Pete68]

The good thing is if u run those tire/wheel sizes your car will have the exact same size as this one, which is badass IMO ; )

[tcolsh]

Thanks for all the help gents!

[/QUOTE]

[tcolsh]

Nice ride...