are they only there to widen the stance?

what size spacers should someome be looking for with 31's and tbar crank?

 

yes they do nothing performance wise...pure cosmetics as far as i know.
what size depends on what you want to do.
1.5" on the rear will make the rear and front tires line up.
some do both front and rear to really widen the stance.

just be aware, that some/most tire shops wont touch your wheels with spacers on...i think its purely a liability issue on their part.

i have had mine on for a year....no problems at all.

i got mine off ebay for around 60 for the pair shipped.
just be sure to get hub centric.

 

Do you think it worth to get wheel spacers for my '95 S10 Blazer?

 

I think the question should be... Do YOU think it would be worth putting spacers on your rig?