Have you tried getting a 3" piece of hose to go over the 3&1/8"...I know the lightish blue stuff go gear sells will stretch, but the thermal flex stuff is a lot harded to stretch....might be just what you need tho to stop it swelling tho.

3" - 3&1/8" is a pretty wierd size....I`ve never seen one in any catalogs, its usually 1/4" steps.

Whens it going to the drags ?