I think I will do what infidel suggested. Can I just pull the tubing out of the back of the guage and reuse the fittings. Or do I need new ones?

 

you may need a new ferel but the rest of the fitting should be ok

 

Another question:

How do I hook up the little nylon tubing to the top of my fuel filter canister? Right now I have a needle valve and that large hydrolic hose going to the isolator.

 

You'll have to use a bushing in the needle valve to get it to 1/8'' pipe thread if it isn't already. Always use new ferrules. Avoid overtightening the compression fittings, they will leak, finger tight plus one turn with a wrench is plenty. Use no Teflon tape, Permatex #2 works excellent for thread sealer. All of the above and you'll have a leak free setup.

 

This is what my setup on my '99 looks like.
Dash mounted gauge, no isolator, stainless braided line, 3 years, no leaks.