Question on rear tire to frame clearance.

roger1

roger1

Master Mechanic
Aug 23, 2010
371
63
San Angelo, TX
Here's a couple of photos of my new GTA/Buick GN 16"X8" wheels. I've got 255/50-ZR16 tires on the rear.





Presently, I don't have spacers on them. While the tires to clear, the clearance on the inside at the top next to the frame rail is very tight. Almost 1/4" on one side but only about 1/8" at the other. I don't have a feel for how much the suspension can move under driving conditions and whether it will ever rub. I did jack one side up and they still clear. Jacked the other side up and still clears too.

So my question to the experts is whether I should put spacers on it?. If so, how thick? Plenty of clearance on the outer side so no worries there if spacers are needed.
 
UNGN

UNGN

Comic Book Super Hero
Sep 6, 2016
2,595
113
Southlake, TX
1/8" ls too small. I would run a 3/16" shim spacer. Make sure the frame rails are smooth with no welding slag that could catch the side waĺl.

On a G-body, zero offset is non ideal in back. Ideal is out anorher 3/8" from zero.

I run GTA Rears in the rear with adapters on both my 2+2 and T-Type.
 
roger1

roger1

Master Mechanic
Aug 23, 2010
371
63
San Angelo, TX
Thanks.
I don't see 3/16 at Jegs but many choices of 1/4". I'd like to get good quality ones too. Was looking at the Baer billet ones. Expensive but I don't want to risk having inferior quality with something like this. I will be replacing the studs with longer ones too.
 
B

bracketchev1221

Master Mechanic
Jan 18, 2018
418
63
Go with whatever spacer you feel comfortable with. I'm using the 7/32" universal spacer on mine. I put a dab of silicone behind it and center it the best I can on the hub and when it dries I put the wheel on. I've been doing it this way for years. When I had the small tires on the Chevelle I used them so they wouldn't rub the inner wheel well. I went 10.30's at 130 with them on it.
 
roger1

roger1

Master Mechanic
Aug 23, 2010
371
63
San Angelo, TX
Thanks guys.
I went out and looked at the car again. I actually have about 3/8 on one side and 1/4 on the other but it's these tags that stick out that cut it down to about 1/4 and 1/8.



Anybody know what the tags are? They sure don't seem to want to come off either.
 
roger1

roger1

Master Mechanic
Aug 23, 2010
371
63
San Angelo, TX
So, If I pry those tags off, I've got 1/4" clearance on one side and 3/8" on the other.
I think I may do some test drives that way and check for rubbing before deciding on spacers.
If I detect any rubbing at all, it seems like 1/4" spacers would be plenty.

Thoughts?
 
Local Hero

Local Hero

Master Mechanic
Supporting Member
Nov 24, 2016
437
93
Northcoast, Cleveland, Ohio
Those tags pried right off on my wagon rails. If that fails you could easily take a grinder to them.
 

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