Weak springs? Here is an easy way to help your tired springs lift your top:
(see pictures below)

You can order your lifting struts from:
www.allegiscorp.com | Door Assists and Gas Spring Mounting Hardware

Purchasing two 20 pound lift gas lifters will produce 20lbs of lift and not 40lbs. If you have a plastic top I would order an AC8720 or AC8730 (depending on how weak your springs are) with a stud hole to fit a 5/16th bolt.

If you have our fiberglass tops I would suggest an AC8730 or AC8740 (depending on how weak your springs are) with a stud hole to fit an 5/16th bolt. I am only suggesting these struts. If you make the struts too strong then you will be placing too much stress on your rollers, lifting arms and wood sub-frame. You could damage your top with too strong of a lifting strut.