Plastic Fuel Tanks?

[Erich Stahler]

I am building a TVR 3000m racer and wondered what the regulations are for non FIA historic race series regarding using plastic fuel tanks, had a look at the HSCC 70's Road Sports technical regs, as a good guide as they are the most stringent race series, but and all it says is:

"The fuel tank must be either the original production specification, or a safety tank. Any fuel tank must comply with FIA Art. 5.5, must not exceed the originally specified capacity, and must be in the original location or in the rear of the car."

I have yet to find the FIA document containing article 5.5 but was wondering what the consensus of opinion was, they can be sourced from the US for quite reasonable money.

Cheers.