Back Space Question??

[Twil]

What is the correct back space for the following wheels on my 87 GN??

Weld 15 x 7 fronts (225 or 235/60-15)
Weld 15 x 8 Rear (275/50-15)

and

Torq Thrust 2 17 x 8 front (235 or 245/45R17)
Torq Thrust 2 17 x 9.5 rear (275/40R17)

Brandon

 

[Roger]

15x7 = 3.75" bs
15x8 & 17x8 = 4.25" bs
17x9.5 = 5" bs - this is approximate.
Bs is measured from the inside edge of the wheel to the mounting boss. These figures are interpolated from the original TR wheels 15x7 with 3.75" bs.