wheel measuring help

[lawrenq]

I'm looking for tips on how to measure for the correct backspace for my Chevelle. The car is mini-tubbed using the abc performance kit and the rear is narrowed 5 inches. I'm currently running a 313/35/20 on a 20x10 with a 5.5 inch backspace with a 2 inch adapter. If I'm figuring this right this means on a 20x10 wheel I'd need a 3.5 backspace to mount the wheel without adapters. I have the wheels mounted as close to the fender as possible. So if I'm planning on running a 20x12 wheel does 5.5 inches of backspacing sound right? I ordered a wheel fit tool but ordered the wrong one for my bolt pattern so I'm debating on measuring for wheels a different way. Here is a pic of the car.

186547

[Lonnies Performance]

In theory... yes. If both the tire & wheel are 2" wider, adding 2" backspace will keep the outside of the tire where it is currently.
Are you certain there is 2" clearance everywhere at the inside?

Also, I'm not sure if you are using the same wheel brand/style, but will the wheel clear the caliper without the spacer?
You can try using your present wheel/tire combo without the spacer to verify inside fitment.

[lawrenq]

Current wheel doesn't clear the calipers without a spacer, I'm going to order the wheel fit tool to make sure I get ot right. I'm thinking about going with forgeline wheels.

[Zspoiler]

Try a local tire shop especially ones that sell performance tires .They have tools to measure wheel offset.

[lawrenq]

I got the wheel fit tool in the other day. Had to mount it backwards to figure out the backspacing. The instructions for it aren't very clear. Looks like a 4.75 backspace on a 12 inch wheel with 335 30 20 with an inch clearance all around. 186834186835

[Canadianwraith]

Very nice set up. How many inches do you have from the inside lip of your fender to the mini tub?

[TheJDMan]

When you order wheels sounds llike you need to specify a tall center pad in order for the caliper to clear the back side of the wheel.

[lawrenq]

Very nice set up. How many inches do you have from the inside lip of your fender to the mini tub?

15 3/4 inches

[lawrenq]

When you order wheels sounds llike you need to specify a tall center pad in order for the caliper to clear the back side of the wheel.

Yeah I ended up going with forgelines so I had to measure the caliper height, width and thickness. Placed the order Monday, I ended up going with the ZX3P wheels, can't wait to get them.

[65 drop top]

Yeah I ended up going with forgelines so I had to measure the caliper height, width and thickness. Placed the order Monday, I ended up going with the ZX3P wheels, can't wait to get them.
Nice choice! What finish did you go with?

[lawrenq]

Nice choice! What finish did you go with?

Polished lips with satin gunmetal centers.

[65 drop top]

Polished lips with satin gunmetal centers.
That’s gonna be sweet!

[lawrenq]

Got my wheels in, everything fit prefect, wish I went with a 345 wide tire on the rear as there's plenty room. 190289190288

[csouth]

Very nice! Yeah, when I ordered mine I just told them C6 Z06 calipers and they got it perfect.

[jus1975]

which wheel fitment tool did you use? I hope it doesnt cost as much as the CCtek tool