He has a tip up door I'm thinking, not a sectional. Springs are relatively cheap James, try the next size up. I have not worked on a tip up door in 30 years, but I do like them. I had a house with a pair of them and opening the door without an opener was easy, what are yours like without an opener? They should be easy if the springs are the right size.
With a regular sectional door you weigh the door without any springs and order, but not sure about a tip up. I often put new faces on garage doors to compliment the house and when done put a bathroom scale on each side of the door and let it down, ad the two together and call and order the correct springs. Not sure how that would work with a tip up?
Wish I could be of more help.