Hi all, I need something cleared up.  I installed the offset trailing from Van Steel.  One of his guys on the phone stated that I could use up to a 9" wheel with 5" backspacing.  But if you look at this pic the spring is allready very close to wheel and these are the stock wheels which are 4.5" backspacing.  It looks like even if I stuck with a 8" wheel and bigger tires I could not increase the backspacing but the new arms will allow more of tire to be under the well....  Is the spring this close on others who have the offset??  Should I stick with 4.5" backspacing and just get a little bigger tire??

Thanks, Ron

Ruready2go38479.2912268518

Good question. I'm expecting my offset t-arms next week, and I was wondering the same thing. In the eckler's catalog it says that you can use 10" with the offsets. Does anybody know the answer to this?

 

From you photo it looks like you could go with the 5" offset.  That's only another 1/2", and it appears you have the clearance.   Remember, that will give you the inside position, the rim width will determin the outer position, based on the inside.

Just the position of the arms will allow for a wider rim, even with no change in offset due to the position of the tire in the wheel well.

ask van steel about various usage and clearances on offet arms..

he appears to be the jedi master on this subject..

 

 

OK guys here it is.
 
You can run up to a 10" wide wheel on C3's. You will have to have a 5.5" backspacing on your rim if you do so. If you plan on keeping 15" rims and want to go to fatter tires your going to have to shorten your spring approx. 1/2 on each side. With 15' rims you have a lot of side wall flex. Now if you go to a taller rim (ie 17 & up) You may not have to shorten your spring because low profile tires have a lot less side wall flex. The shortening of your spring depends on what size rim and tire combo you want to go with. I try to ask everyone what rim and tire sizes they want to go with so I can get them the correct parts the 1st time though. Also offset t-arms do not move your wheels in or out. It only bends the arm for more tire clearance and relocates the parking brake bracket to the top of the arm. Let me know what tires and rims you plan og going with and I can help you out.

On the front, go no larger than 8" wide and use a 4 " backspace.

Rears,
9" wide rim, 5 " backspace
9.5 wide rim, 5" backspace or 5.5. Either will work. This will depend on your tire size.
10" wide rim 5.5" backspace.

Hope this helps. If you have questions, you can always call me. 800-418-5397

Dan

Thats basically what I found out doing the article for Corvette Enthusiast.

Most aftermarket fibreglass leaf springs, like those from VBP, are already a 1" shorter on each side.  VBP also told me if you use their center mount rear leaf spring you can get away with a 11" rim with a 295 tire.

I still played it safe with a 255 on the rear so if would tuck into the wheel well and a 245 on the front.  My rear tire was a 9.5" wide rim with a 4.75" backspace on front 8" with a 4" backspace.

You all need to pay attention to each tires. section width and what the tire specs are with its give mounted width they give on their data sheets.

If the front backspacing was 4.5 with stock rims why go to the 4.0???  Woundnt this make the wheel stick out more??

[QUOTE=After Shark]

Thats basically what I found out doing the article for Corvette Enthusiast.

Most aftermarket fibreglass leaf springs, like those from VBP, are already a 1" shorter on each side.  VBP also told me if you use their center mount rear leaf spring you can get away with a 11" rim with a 295 tire.

I still played it safe with a 255 on the rear so if would tuck into the wheel well and a 245 on the front.  My rear tire was a 9.5" wide rim with a 4.75" backspace on front 8" with a 4" backspace.

You all need to pay attention to each tires. section width and what the tire specs are with its give mounted width they give on their data sheets.

[/QUOTE]

10" wide rim. Wheel well is only 11". If you have an 11" wheel and you hit a bump hard, kiss your fenders good bye. 295 will still work on a 10" rim. 11" rim will work if you have flares or some frame mods.

 

[QUOTE=Ruready2go]If the front backspacing was 4.5 with stock rims why go to the 4.0???  Woundnt this make the wheel stick out more??[/QUOTE]

Yes but most people get rims with big wheel lips.

 

Correct.  Intro Wheels said that anytime you get the new style Rolled lip style rims you need to add a 1/2" to the final dimension to get the outside mounting rim width.  Did I just confuse you?  So basically if you go with a 9.5" Rim with a rolled lip out total width on this rim as mearused will be 10".  You also need account for this in the backspace.