Rear Tire Clearance

[cst350]

I realize there is alot of thought on this that has been posted before but I haven't found one to answer my situation yet.

I have a 69 with 4/6 ECE drop. The front spindles are ECE disc conversions and the rear end is the stock 6 lug from '69

I want to go 16 x 8 front and 16 x 10 rear. I have "builder wheels" on it now of the same size and 4.5 BS both front and rear. The rear tires, 275/60/16, are only a half inch away from the fender well! Cant be right... I read that my rear end is .75" more narrow than later years. Should I go with 3.75 BS? That would give me 1.25" of clearance.

I tend to like the look of the big tire filling the wheel well so I want to keep the diameter the same.

Any thoughts?

[Hart_Rod]

You've got the backspacing wrong. Less backspacing pushes the wheel out, not it. Check out this link:

https://www.rsracing.com/tech-wheel.html

For a 10" wheel, you need a of a 5" BS with the early rearends (67-70) for it to fit correctly (5.5" for the 71/72).

I'm running 4/6 drop with 20x12's and a 31-16 rear tire (first 2 pictures). I have a 7" backspsacing and the wider rearend (my truck is tubbed). If I have a full tank of gas and hit a really hard bump, my rear tires will just lightly scuff the inner part of the outside fender lip. I plan on building a narrower 67-70 rearend or installing a narrowed 9" just for added clearance AND just in case I want to go lower, . The second set of pictures are 20x10s with a 5" BS. They are the wheels off of my 69 suburban. They fit really well, but most guys go with a 5.5" BS for the 71/72 rear ends, especially if they are going to lay them out. Good luck.

[bigguy69]

i have been gettin backwards to. thanks hart rod!

[cst350]

Thanks Hart_Rod! Your second set of pictures has the look I like best... all about the old school lip. Sorry to be so thick on this but... the way you explain it the BS is measured from the front of the rim, yes. Either way I know I need to go out about .5 inches. Just trying to get it right before laying down what is pretty big money for me.

CST350

[Hart_Rod]

Originally Posted by cst350

Thanks Hart_Rod! Your second set of pictures has the look I like best... all about the old school lip. Sorry to be so thick on this but... the way you explain it the BS is measured from the front of the rim, yes. Either way I know I need to go out about .5 inches. Just trying to get it right before laying down what is pretty big money for me.

CST350

Backspacing is measured from the wheel mounting surface to the inside wheel lip. For example, you always add an inch to the wheel size to determine the overall measurement, a 10" wheel measures 11" from the inside wheel lip to outside wheel lip.

So, a 5.5" backspacing would put you at the center of a 10" wheel (11" total width, 5.5 BS in the rear and 5.5 in the front). A 4" backspacing would provide you with 7" from the wheel mounting surface out and 4" BS from the wheel mounting surface in. A 7" backspacing would provide you with 4" from the wheel mounting surface out and 7" BS from the wheel mounting surface in. Clear as mud?