With roughly 5,110 households in Rio Vista, this isn't a town where we keep a dedicated stock trailer the way we might closer to Antioch - every spring job here gets the right part pulled and loaded before the drive out, based on what you tell us about the door. If the door's older than the 2002 median, or it's been modified with a different opener or added insulation, we may need to confirm the spring spec by phone before the truck leaves, which can add a short delay.
One limitation worth saying plainly: if the issue turns out to be a bent track or a failing opener rather than the spring, that's a second problem on the same trip, and parts for some openers aren't something we carry on the truck for every make. We'd rather tell you that up front than have you wait on-site while we sort it out.