Another B.S. Question...and yes I have read the FAQ :)

[70cst]

Five lug 5x5 fronts. 4 1/2" Drop 2 1/2 Drop Spindles 2" drop coil.

In the fronts...I have 2 1/2 Drop Spindles and will soon install 2" Drop Coils. I realize the B.S. of factory Ralleys are 4" (I believe). I am going with 15" TT II's on the front. The 15x7 TT II's I can only go 4 1/4" B.S. while 15x8 I can go 4 1/2" B.S.

So the question is...Does anyone have a front drop of 4 1/2" with 4 1/4" B.S.? I am concerned with the inner wheel rubbing the control arm which the Ralley's did.

I have done a lot of searching for answers to my question but have not really found the answer to my question. The TT II's are special order so I want to be right the first time.

Thanks in advance.

[lolife99]

I wouldn't do it.
A 4" backspace on a 15" wheel is really close.
Throw your suspension together and look at a steel ralley wheel.
Then try to add another 1/4"-1/2".
You might make them clear when the wheels are straight,... but the wheels turned lock to lock will be worse.

You can go up to 17" rims,...
I've had 17x8's up front (with a 5" b.s) and it worked fine.

[lolife99]

What about the the Torque Thrust D's?
(I know,... gray centers,...)
I think they come with a 3.5" backspace.

[70cst]

The questions is...

Will a 4 1/4" B.S. be cutting it two close? The only way I can go with a 15x7 is with a 4 1/4 B.S.

The 15x8 TT II's are avaliable with 4 1/2" B.S.

I know 4 1/2" B.S. will work and the inner wheel will not hit the control arms.

I have 16x8" TT II's on the rear and they do fine ...but they are to tall in the front and hit the inner fender with a 4 1/2 front drop. The B.S. is fine.

This is the reason for my questions...

Thanks in advance.

[lolife99]

Originally Posted by 70cst

The questions is...

Will a 4 1/4" B.S. be cutting it two close? The only way I can go with a 15x7 is with a 4 1/4 B.S.

The 15x8 TT II's are avaliable with 4 1/2" B.S.

I know 4 1/2" B.S. will work and the inner wheel will not hit the control arms.

I have 16x8" TT II's on the rear and they do fine ...but they are to tall in the front and hit the inner fender with a 4 1/2 front drop. The B.S. is fine.

This is the reason for my questions...

Thanks in advance.

If you know a 4-1/2" will work,... then so will a 4-1/4".
(that's less backspacing)

I'm not sure I understand?!?

[70cst]

Originally Posted by lolife99

If you know a 4-1/2" will work,... then so will a 4-1/4".
(that's less backspacing)

I'm not sure I understand?!?

Ok...
Maybe that's my problem. I have been thinking of B.S. backwords.

A Ralley wheel has a B.S of 4" and it will rub the control arm on a sharp turn....but it barely rubs.

So if I understand this correctly...4" or less then the inner wheel will rub while 4 1/4" or greater and I will be in good shape.

Am I on target???

Again thanks.

[lolife99]

You are backward.
Backspacing is measured on the backside of the wheel.
From the center of the wheel,... to the inside lip of the wheel.
For 15" wheels anything from 3-1/2" to 4" of backspacing will work with a little a-arm trim.
Anything GREATER than 4" will rub.

[70cst]

Originally Posted by lolife99

You are backward.
Backspacing is measured on the backside of the wheel.
From the center of the wheel,... to the inside lip of the wheel.
For 15" wheels anything from 3-1/2" to 4" of backspacing will work with a little a-arm trim.
Anything GREATER than 4" will rub.

Ok...
Thanks!!!
That answers my question. You get a "Gold" star for instruction for 67-72 Trucks Suspension 101.

[lolife99]

Here's a pic,...

[lolife99]

Put a set of 17's 18's or 20's on and be done.
8" rim with a 5" backspace up front.

[70cst]

Originally Posted by lolife99

Put a set of 17's 18's or 20's on and be done.
8" rim with a 5" backspace up front.

Great idea and I like it but...after spending all the $$$ on the resto of the Circuit Rider it will be a while before I will have the extra $$$ for four new tires and wheels.

For the time being getting two new wheels/ and tires is the best economical route for me.

Unless I will the lottery.

Again...thanks for the info as it is greatly appreciated. That is what makes this forum so special is the assistance that is given when one has an inquiry.

[68Stepbed]

I would just get the 15x7 in stock bs. I beleive it's 3.75"

[mrh33916]

I'm not a big fan of wheel spacers but some people do run them.

If the wheel you are looking at only comes in 4.25 backspacing you might want to add a 1/4" spacer to get back to 4" of backspacing.

Another option if you really want to run that wheel would be to extend the steering lock tab on the lower control arm out just enough to keep the wheels from rubbing. (This is what I would try in your situation if you are determined to run that wheel and backspacing)

[Stano]

I am running 15x7 ralleys on front with 2.5 spindles and stock 6 cyl springs with a v8 it sits pretty darn low. I dont know what the overall drop is for sure but I need to go to a larger dia. rim. If i use drive on wheel weights on the inside the control arm will knock them off and man it sounds like the frontend fell out and i ran over it. lol Wheels do flex also when you are driving so take that into consideration when they are runnin that close.

[70cst]

TT II's 15x7 5/5 -6mm 3 3/4"

Ok looks like I am good to go as the above wheel will do just fine. For some reason my thinking was backwards to my undertsanding of B.S.

The 15x7 wheel will tuck into the fender nicely and I will have my 4 1/2" drop without any rubbing issues. My back wheels will be 16x8 which look just fine.

Again thanks for your input as it is appreciated.