I recently installed a new 2 piece fiberglass shower. Now, the diverter is located too far back from the shower wall to reinstall the cover plate and handle assembly. Does anyone make an extension for a Delta Single Handle Faucet assemby to compensate for the difference? Or is there another way to solve the problem?

How too far back is the valve and how did you mount the valve to the wall? You don't have a very large opening to work with, can you pull it foreword at all? If its just a hair try getting a similar but longer screw to pull the faucet forward. Once the faucet is in the right location install the correct screw in the other hole, then replace the long screw with the right one. This is only if it's a hair off, you don't want to have too much tension/torque on your pipes.

Unfortunately, it's about 2 inches off. Which is basically the width of the fiberglass formed sidewall. Thanks for your quick reply.

Two inches is too much for the pipes to bend. How is the faucet attached to the wall, can you get at your attachment?

Yes, the valve body is nailed to a stud.

Try to pull the nail or even drill off the head. Sounds like you have a peretty large cavity between the studs and the fiberglas.

Yeah, this is a fiberglass unit that replaced an original ceramic tiled shower. The cavity distance is the width between the wall studs and the inside housing of the fiberglass enclosure. I just figured there was a stem extension kit that would solve the problem. I've seen these for 2 faucet models, but I've yet to find on for a single shower faucet.

Maybe some of these will help. delta faucet extension - Google Product Search

THANKS! You've given me a starting place to solve the problem. This is what I was looking for. I sincerely appreciate all your help!

If you want the best advice try to contact Speedball1, he's one of the experts and a great plumber. Always ready to help and has great pics and diagrams. Not sure why he hasn't jumped in here. Good luck pal

If it's an older style with a ball assembly instead of a newer style with a cartridge, then you're out of luck.

Extension kits are available for the newer cartridge style shower valves, but it's doubtful you'll find one that will extend it 2 inches.

If it's in an interior wall, you may have to open up the wall behind it to move it forward.

Try to contact Speedball1, Always ready to help and has great pics and diagrams. Not sure why he hasn't jumped in here.
I try not to interfere when a experts doing a good job of replying to a question but since you ask click on Delta faucet repair parts from FAMOUS PLUMBING SUPPLY
And scroll all the way to the bottom of the page and find #RP25592 Extender for Diverter handle stem for $4.25.
I don't know whether this will fit your shower valve but it was all I could find.
If that don't get it then you're going to hafta open up,the wall and reconfigure the shower valve like growler sez.
Good luck, Tom