1978 GMC Suburban 1500 4wd Bolt Pattern


Bolt Pattern
6x139.7mm = 6x5.5 inches
Tire Sizes
Option 1
225/75R15 = 28.3x8.9R15
Option 2
235/75R15 = 28.9x9.3R15

The 1978 GMC Suburban 1500 4wd bolt pattern is 6-139.7 mm. This means there are 6 lugs and the diameter of the circle that the lugs make up measures 139.7 mm or 5.5 inches across. To get a close measurement of your 6 lug bolt pattern without a bolt pattern tool you should measure from the center of one lug to the center of the lug across from it.