10 Bolt 70 Chevelle- Weld RT-S 18x10 Backspacing

[Shiner]

modifications in siganture

[Vince@Meanstreets]

It is best to measure for yourself since all cars are different.

From the cars we get in the shop the average is 5 3/4" to 6" back spacing. One was 5 1/2" but that was due to exhaust tailpipe routing.

[Shiner]

If I have 15x8 5.5" BS and I like the way the fill the wheel wells and I then want to put a 10" wheel would I need to get a 7.5" BS(to accommodate for the 2" wider wheel?

[Vince@Meanstreets]

Originally Posted by Shiner

If I have 15x8 5.5" BS and I like the way the fill the wheel wells and I then want to put a 10" wheel would I need to get a 7.5" BS(to accommodate for the 2" wider wheel?

So a 15x8 and a 5.5 BS will actually take more due to tire bulge. Im assuming you are running a 255 tire? 255 on an 8 is 3/8" average. The actual back space available would be 5 3/4" taking the tire bulge into account.

On an 18 or 17 wheel the tire bulge is less.

I would measure what you have then subract an 1" min for articulation room. For a 305 or 315 on a 10" wide you will need 12" of space. Average 70 Chevelle wheel tub is 14-14 1/2" wide. 1/2" to the outer and 1 1/2" to the inner should do.

Jack up the back and pull the wheels. Let see what you have?

[Shiner]

Wish you would just tell me, "Travis get the rears with 6" BS and the fronts with 5""

[Vince@Meanstreets]

Originally Posted by Shiner

Wish you would just tell me, "Travis get the rears with 6" BS and the fronts with 5""

Now what fun would that be.

Actually I would if you would let me measure the car first but you are going to have to get dirty to know for sure. You have everything there to get the answer you need.

With the tire on the car, measure distance from the inner well to the inner tire. Closest section to hit.

Now measure the outer tire face to the wheel well lip. Quarter panel lip.

Pull the tire off and measure the current tire width. Sitting on the ground on its side. Measure the width. Ground to the top of the tire. 8" wheel should be around 10-11" wide. This is the section width.

Now take a measurement of the wheel well to the quarter panel lip.

Now use a ruler and tape measure to measure wheel mounting (axle flange to inner wheel well) pictured^

let me know when you get all of that.

[Shiner]

Will try and do it tomorrow, thanks Vince

Can you get me a good deal on some S71s?

[Shiner]

Originally Posted by Vince@Meanstreets

So a 15x8 and a 5.5 BS will actually take more due to tire bulge. Im assuming you are running a 255 tire? 255 on an 8 is 3/8" average. The actual back space available would be 5 3/4" taking the tire bulge into account.

On an 18 or 17 wheel the tire bulge is less.

I would measure what you have then subract an 1" min for articulation room. For a 305 or 315 on a 10" wide you will need 12" of space. Average 70 Chevelle wheel tub is 14-14 1/2" wide. 1/2" to the outer and 1 1/2" to the inner should do.

Jack up the back and pull the wheels. Let see what you have?

Outer: 1"
Inner: 2"

Section Width 11"

Weld recommended I go with a 6.1 and run .25" spacers if I need to.

[Vince@Meanstreets]

need one more bit of information. The backspace including the tire.
Im guessing you will be 5 7/8"

[Vince@Meanstreets]

Originally Posted by Shiner

Outer: 1"
Inner: 2"

Section Width 11"

Weld recommended I go with a 6.1 and run .25" spacers if I need to.

How many inches to that shock bracket to your current tire?

I am measuring 4 7/8" from the wheel mounting flange to the edge of the mounting stud and a radius of 7" so a 14" circumference. The inside of an 18" wheel is 17 3/4 so I believe you should be good. Also depending on lower shock mounting type. I can see that reducing the gap by an additional inch. Another good reason to got to a DSE OR Ridetech rear coil over system.

good catch guys.