I believe they are 5 on 5.5... No...that is incorrect. Ford uses the 5x5.5" "Bolt Pattern" on their 1/2 ton trucks/vans etc. The Bolt Pattern for Chevy Astro and GMC Safari Vans are 5x5". Which is the same as GM Full-Size 1/2 ton 4x2 trucks/vans and some full size (RWD) passenger cars.
left to right
5x4.75
5x127
if you are talking about the bolt pattern on your wheels they are 5 x 4.75
The bolt pattern on a 1969-1991 K-5 Blazer is 6 on 5.5" (139.7mm).
Chevy 10 bolt rear
5x127
The bolt pattern for the Chevy Equinox is 5-115.
5X5 big Chevy bolt pattern
Bolt pattern for WHAT???????
bolt pattern for these model smaller chevy's is 5x4.75
sedan is 5x4.75 station wagon is 5x5 In 1991 all B-bodies switched to a 5x5 pattern.