Springs for BEC Fury live axle for track use?

Hi all

Can anyone please give me some starter guide settings/opinion for what weight/length springs should be suitable for track setup please?

Car is a Fisher Fury, live axle with ZZR1400 engine.

I bought the car ready built (when it had a 900RR engine in it),so have no idea what springs are on it currently. Cant see any markings either.

Thanks for any help!

Cheers
Les Otter