Obviously you have the wrong parts for the job.
Have you contacted your dealer for the correct replacement part?
Personally, I would inquire about getting the correct parts.
Depending on the year of your vehicle they may or may not be readily available.
Finding a used line is also a possibility.
Doing what you are trying to do, kinda worries me when dealing with fuel.......is it gonna work....will it hold??
Not with using these "repair" kits.
If we run into issues, we replace the complete line.
Welcome back Tommy!
I've done a few of these, but I haven't had a problem getting them to go over the line on the truck. You're positive you've got the right repair kit? They do come in three or four sizes, and I'm wondering if you've got the right one. I haven't used one from Autozone because there isn't one anywhere near where I work, we've always gotten them from the Help section at Napa or Standard Auto parts and they've slid right on and worked perfectly. If you have another parts store close, or if there were more options at Autozone, take your old line with you and see if there is one that is a better fit. The repair line for a 5/16" line is going to be a bit bigger than 5/16" before you shrink it.
The torch thing bothers me too! I would stick with a heat gun to shrink this, and make sure there is no fuel in the area. Get the tank away, make sure the fuel line is disconnected at the engine and blown out with compressed air and completely dry. Have a helper with a fire extenguisher in the area. As you and Mark had discussed, this can be pretty dangerous stuff.
Napa will likely have a heat gun. My dealer is in a pretty small town without a whole lot of options for parts stores, and we've always had a heat gun within 20 minutes of asking for a new one, so either the Standard Auto Parts or the Napa (or both) have them in stock around here. I would think they would have one at your store, Napa's are always pretty good.
Your Autozone guy scares me...