I have build my 98 model 12 valve's engine to preform how I needed it to but at the same time I have build a strong enough motor that the transmission can not hold up. transmission is slipping in first and second and will not lock up, but when if and when it shifts to overdrive hold on to your hat!!!!!!!!!!!! I have looked at Goerend transmission's and Ats transmission's. Which one has best transmission and service?