Carrera center fill gas tank.

Do you want to use a stock 356 Porsche gas tank with an extended neck ?

Will it fit since most fiberglass speedsters were made to use a VW bug tank ?

Umm, just use a new regular tank and get a filler from Greg for a Spyder. Actually, you could get the tank from them, painted whatever color you'd like. They first move the sender location to the side.

You'll still have to cut your hood out and repaint. Then you'll have to also figure out some kind of system to handle drainage through the hood.