[turbo23dog]

If your car has been sitting 20+ years, you may well have a problem with rust in the gas tank.

On my 73 911T with Webers, I had a continuous problem with backfiring that eventually was traced "dirt" in the carbs from rust in the gas tank. I'd clean and balance the carbs every month and it would stay good about that long until the backfiring would start again. I eventually disected the fuel filter and found the rust particles.


I got advice from others to pull the tank so that's what I did. I brought it to a local radiator shop where they cured the rust with a Muriatic Acid flush and then sealed the inside of the tank with some product (can't remember the name) that is impervious to fuel. Its something you will want to check out as you proceed on your new addition.

Hope this helps. Good Luck.