Wheel & tire fitment

[Quinn]

New user and I'm looking for some help.
I have an 87 caprice classic, qa1 coilovers, stock dimension ford 9 in rear and I'm wanting to know how wide a wheel and tire combo I can use on the rear.
I want to run a 15x8 with a set of MT 275/60/15 Drag radials. Is this possible?
Thanks.....

 

[GoodOldsGuy]

New user and I'm looking for some help.
I have an 87 caprice classic, qa1 coilovers, stock dimension ford 9 in rear and I'm wanting to know how wide a wheel and tire combo I can use on the rear.
I want to run a 15x8 with a set of MT 275/60/15 Drag radials. Is this possible?
Thanks.....

I have no idea how far out that axle will hold the wheels, but my gut tells me that a 275/60x15 tire would need a wheel wider than 8”. The road surface contact area of a 275/60 should be a bit wider than 10”. I’m confident that those tires will extend beyond the quarter panel (where they will be damaged on suspension compression). Again, I don’t know where that axle is going to put the wheels but that’s a lot of tire/wheel assembly to stuff under the quarter panel and I’d be amazed if they didn’t get hung up on something. I do know that if your Chevrolet had the stock P or B axle there’s no chance of making that combo work without some elaborate wheel spacing and plenty of quarter panel modification. I have a similar B Body with 235/70x15 on 15x7” wheels that fit in the wheel wells, but that’s the maximum that space allows. I’m sorry I can’t give you more precise advice but that’s what I know. Your wheel offset is going to be a factor in figuring it out as well.