Offset/Backspace on OEM 15x8 Rally Steel rims from my 87 C10?

[cyberpine]

Anybody know what the Offset/Backspace is on my 15x8 OEM Rally Steel Rims might be on 87 2wd C10?

Currently running 31x10.5 tires and they seem to sit way into the well.

I'm looking to run Steel 15x10 Cragars with -44mm Offset and 275/60/15s tires on it.

Also, can anybody comment on how much wider at 275/60 tire will look on 15x10 vs 15x8? It would appear to look signficantly wider from the trucks I've seen on the road.

According to the calculator it's 10.8 wide by 28 high. I use to run 275/60 on 15x7.5, and it looked wide, but nowhere as wide as when I saw it on a 15x10.

Thanks.

[flamingbig10]

should be 4" of bs

[cyberpine]

Originally Posted by flamingbig10

should be 4" of bs

Thanks.

so If I apply this formula

Back Space to offset conversion:
take overall rim width including outer lip (usually listed rim width + 1"), then divide by 2, then subtract that number from the measured backspace, then convert that number to metric by multiplying by 25.4.

4 - (8+1)/2) * 25.4 = -12.7mm offset .. could that be right?

So, if a 15x10 rim is offered in backspaces 2,3 and 4 and I wanted the rim to sit out further .. would I go with with a 2 inch backspace

(2 - (10+1)/2 )* 25.4 = -88.9mm offset... something sounds wrong with that .. or maybe a 15x10 with 2" inch backspace would just be crazy .. I have read that it's offered somewhere.

(4 - (10+1)/2 )* 25.4 = -38.1mm (which sounds right)

This is the rim I'm looking at:

Cragar 365 V-5 -44mm offset

Can somebody tell me what the backspace on this rim would be?

I'm hoping it will stick out just a tiny bit out of the wheelwell.

Thanks.

[flamingbig10]

the cragars will sit a little past the wheel well opening

[lolife99]

A 15x10 with a 4" bs will stick out 2" farther than a 15x8 because the wheel is 2" wider.

Look at this chart that I save:
A 15x10 with a -44mm offset = a 3.75" bs

This wheel will stick out 2.25" more than your 15x8 ralley wheels.

[JCampbell]

Confused. lol

What kind of offset should I be looking for with a 15x7 and 15x8 wheel?