Possible gear choices biggest bell set up> first gear 22 from the RS4-3 --- second gear  23 -24 - 25 pinions to be made .---------- Caution ------ This set up is for big engine speed drivers only . What is the purpose  ?? Have no Idea ask them . Like one of the drivers said “ I have the need for Speed “ his words not mine-- unfortunately I agree --unfortunately -yes it cost’s money - big money to go fast .