I have another question and I apologize for all the questions.
I kept within the same title theme as the rear question so I could find it later

Question are about stock '74 C3, no fender flares.

A) What is the clearance between the inside of the fender and the frame in the front wheel well? Rear is 11"

The following is just for people who are bored and feel like chatting away sharing info

B) I see most people use 8" wide wheels in the front of the C3. Presumably clearing body parts while turning the wheel is at play. Which body/chassis parts are the problem? Info on the above could help understanding why certain choices are made.

C) I have seen as wide as 9,5" wheels up front. Does this only work because you change the overall height of the tire to something like 26" even though the tire will be wider as you decrease the series on the tire to 35 or whatever?

D) What I'm getting at is that an 8" wheel will allow for better filling of the wheel well up front than a wider wheel without causing interference while turning the steering wheel to the extremes of rotation? What I'm saying is that a narrower wheel allows one to install
a taller tire like 27,4" or whatever

I'm still calculating stuff, just trying to make sense out of it for myself.

I'm on the verge of buying 9,5" wide front wheels with 275/35/18 tires and I know it works as I've seen it installed on this forum. Somehow I think that it should not work without some type of interference when turning the steering wheel to its limits. I'm missing something and don't know what, therefore the questions.

 

Hi Summerfun,

I'm pretty sure the original wheel size is 15X8 with a 4" backspace. I went with an 18x8" wheel with a 4 inch backspace to avoid any clearance issues, however you are correct that I have seen other's on the forum whom have installed wider wheels on the front and back.

I believe that to avoid any interference issues they have gone with greater backspacing on the wheels and in some cases have also installed wheel spacers. I'm not sure if all the extra effort is worth the extra wheel width. JMHO.

 

I don't mind using wheel spacers at all.

A 9,5" wide wheel (10,5 in real world terms) with 4"backspacing created with a spacer will have the wheel stick out from the hub 6,5".
I'm pretty sure that there is way less space from the hub to the fender.

That's exactly why I think that I'm missing something. How do people get that 9,5" wheel to fit in there without sticking outside the fender by a mile.

Hence the question about the distance from the chassis to the fender.

As far as I can remember (and this is a big guess) there is 4,5" from the front hub mounting surface to the fender. If that was correct a 9,5" wheel has to have a 18mm (my guess of what 3/4" is in mm) offset or less to stay inside the wheel well. That means that I have to be able to clear 6" of backspacing in order not to have the car look like Rover.

I don't know, but I know I'm missing something

 

http://forums.corvetteforum.com/c3-t...nd-wheels.html


http://forums.corvetteforum.com/c3-g...ghlight=wheels

 

http://forums.corvetteforum.com/c3-g...-thread-7.html
Post #127 and #133

 

the fender flairs changed in 1970, I have 18x9 with 4 7/16bs in front on my 68, they only stick out 5/16" more than my 16x8 with 4"bs. I ordered 18x9.5 but the guy at Fiske got that wrong. the 18x9 are just inside the fender when you look down. if you go to their website they have a chart to help determine which wheel and backspacing to use and very helpful. sorry can't be any help on running 27", I'm running 26s up front, with no clearance issues.

 

Not questioning what you're saying but I want to be 100% sure. :-)

18 x 9,5 wheels with 25mm offset is 6,25" backspacing
If I use a 1" spacer like you did it leaves 5,25" backspacing.
Apparently you clear that without rubbing anywhere in the front wheel well which is absolutely great!!

Just asking because everything that I've seen is people going for 4,5" backspacing up front or less. I presume that is just to make the tire/wheel look better inside the wheel well. I always thought that it was because anything more that 4,5" backspacing up front would rub on the inside.

Again, not questioning you but I want to be 100% sure that I understand correctly and that I'm not misinterpreting anything before I buy those 9,5" wheels and 1" spacers for the front

Again, I apologize as my intentions are not to torment you

 

I would double check those numbers up front. I have 18 x 9.5 up front (with L88 flares) with 4.5" backspace and I only have about 1/2" space between the wheel/tire and the steering arm. Steering arm cant be moved. So I would think 4.75 backspace is your max. My car is lowered and I'm running a 285/40 up front and the tire will just touch the chassis rail on full lock.

Nick

 

Wow researching this can get confusing...lol
So many different opinions.

Just found this.....


http://forums.corvetteforum.com/c3-t...-they-fit.html

It seems a few have done it and some say impossible. I'm still searching for the distance between the fender and the chassis.

lvrpool32 I believe you are correct and that 4.5" backspacing is what I have to calculate bolt on spacers to achieve in the front. I may get lucky and clear 3.75"-4" backspacing as others have achieved

The numbers look harsh but I guess in real world terms 1/2" is splitting hairs. On the other hand that same 1/2" can cause you to bang your head against the garage wall in frustration.

I'm actually enjoying this....at the risk of frustrating well meaning other posters.
In all truth I'm just trying to find the correct numbers.

I appreciate the patience!! Thanks for all the great info and help. I really appreciate every bit of info from everyone.

 

I hate to say this but.........just because something works on one car doesn't mean it's going to work on another. That's why I suggest you test fit something that's close. The main advantage you have when using adapters is you can adjust the backspace as needed with the thickness of the adapter. The other thing is if you are dead set on running 9.5s" and 275 tires all the way around buy only the rear tires and test fit them in the front. If you are too close in the front you can always drop down a tire size or two for a little more room. Large diameter wheels (17s or bigger) usually offer a bit more backspace as the suspension (tie rod ends and/or upper ball joint) sometimes fit inside the wheel hoop. Then the frame becomes the limiting factor when turning wheels. Yeah trying to stuff max wheels/tires under any of these "classic" cars will make you........