[c0sie]

Just pick a pinion, any pinion between say 18 and 23 (for reference I went onto a random number generator just for you and it told me to use 22).
Stick a 22 tooth pinion on it and mesh it up.
Get to your local club early, help set the track up, smile, sit down.
Get your car out in practise and see if it revs out about 3/4 of the main down the main straight.
If it does, result!
If not, gear it up or down depending on how it feels.
If you have problems ask a club member, remember to say please and thank you.
Sit down again.
Remember, no one at the club is deliberately trying to break your car etc etc (just before you come back here saying so).
Help pack up, say thankyou and good bye to everyone.
Go home, your home no one elses.
Take your meds.
Let us know how it went.