65-66 Knock off wheel backspacing

[Jim V.]

Does anybody know the actual backspacing on 65-66 alum knock off wheels?

I understand the offset is 7/16 and the wheel width is 6 inches. Given this, the backspace SHOULD be roughly 4.0 inches. The forumula would be:

Backspace = wheel width/2 + offset + flange width
3 15/16 inches = 6/2 + 7/16 + roughtly 1/2

Is this correct? Based on the existing clearances to the emergency brake with my stock steel wheels I have less than 1/2 clearance. The stock steel wheels have a measured backspace of roughly 3 11/16. Given this the KO should be + 1/4 or... 3 15/16

I am sizing some Wheel Vintiques 6 inch wheels and I am trying to match the known backspacing of the factory knock offs. WVI offers 3.5 and 4.0 backspacing in their 15x6 30 series wheel. I prefer not to use the 67 DC spec with a 3.5 backspace since the DC spec would effectively move the tire outboard, compared to the 65-66 steel wheel, by 5/8 inch. Given I would like to run wider than stock 215/70 tires, I am trying to avoid front fiberglass issues.

Thanks...

[Duke W.]

Re: 65-66 Knock off wheel backspacing

Including the adapter the offset is .060".

Duke

[Tracy C.]

Re: 65-66 Knock off wheel backspacing

You also need to consider the clearance issues brought on by a 4.0 backspace with regard to the frame, trailing arms and the tip of the rear spring.

tc