wheel fitment question (not Buick)

[tom h]

Didn't get much info from 1-2 chevy truck forums ... I may get more knowledgeable answers here !

vehicle: 1994, 4WD, full size K1500 Blazer. Stock suspension and ride height. Same basic chassis as Suburbans & K1500 pickups.

stock tire: 265-75 x 16"
stock aluminum alloy wheel: 16x7, 5.75" rear space (I am not 100% sure of rear space).

I have a chance to pickup some nice Centerline truck wheels at a good discount. Problem is, "All Sales Absolutely Final". Even if I don't mount the tire, and just loosely attach wheel to the vehicle to estimate clearances, I cannot return.

Centerline wheel: 16x 8", 4.5" rear space.

So-- the outside edge of stock tire will move outboard:
0.5" due to wider wheel, plus another
1.25" from the decreased rear space, for a
TOTAL tire movement = 1.75".

Estimating off my existing stock tires and wheels, on the Centerlines I suspect I MAY have a clearance problem between the outboard edge of the front tires and the hard rubber spoiler under the front bumper -- or maybe even even with the wheel opening. But it's difficult to tell ...

So it's a long shot, but I thought I'd ask if anyone has actually run a 16x8 x 4.5 BS wheel on their 1994-ish 4WD full size Chevy truck or SUV ... TIA

 

[John Larkin]

I don't know how long your studs are but maybe you could slip a 1" thick piece of wood behind your current wheel and test the turning interference with the fender and wheelhouse in your driveway. At least you'd have a bit of an idea.

 

[tom h]

Originally posted by John Larkin
I don't know how long your studs are but maybe you could slip a 1" thick piece of wood behind your current wheel and test the turning interference with the fender and wheelhouse in your driveway. At least you'd have a bit of an idea.

Interesting idea ... even a few threads engagement (on 1 wheel) ought to be OK for driveway test.

 

[John Larkin]

Yes with a floorjack under the a-arm so it loads the suspension but the tire doesn't "have" to carry the weight of the vehicle.

 

[tom h]

Didn't try a wood "spacer" behind the wheel-- but I did take a compass-style measuring caliper set to 1.75"-- the calculated distance the outboard edge of tire would move-- and started measuring clearances at various steering wheel postions.

Pretty clearly, the proposed new Centerline wheels would have reduced worst case tire-to-wheel well clearances to essentially 0, under some conditions.

No go.

The wheels would probably fit fine if one had a modest body or suspension lift, but I don't want to mess with it.

For anyone interested, Centerline was offering:

"Bullet" forged alumimum wheels.
chromed (not just "polished")
16x8 x 4.5BS
6x5.5 lugs for 4WD chevy/GMC trucks
$200 each.
Not blems, cosmetically first-line.

Summit Racing was charging nearly $300 a few months ago.

 

[tom h]

UPDATE:
I checked my actual stock aluminum wheel and the backspace is 5.50", less than the 5.75" of the steel spare tire. Lesson learned -- don't assume.

Therefore -- with new Centerline wheels having 4.50" backspace, the outside edge of stock tire will move outboard:

0.5" due to wider wheel, plus another
1.0" from the decreased rear space, for a
TOTAL tire movement = 1.5".

Now, my worst case clearance from outbaord edge of stock tire/wheel to the rubber air dam under front bumper is about 2" .

With the new wheels the worst case clearance will reduce to 0.5", which is tolerable (unless I ever put tire chains on the front!).