3rd to 4th is the shift that causes the most problems. Bends the fork and then all your shifts become hard. Grand gears, metal in transmission until everything falls apart.

For the street and NA, 04-08 trans will work fine. Plenty of boosted rx8's are using the 04-08 trans with no problem and many of them track the car. The extended WOT driving that the GrandAm cars do creates a lot of heat and stress on everything which starts causing the week points of the car to fail.

For me 300+ RWHP I am not worried about street driving and on the tracks I drive, I shift into 4th 2-3 times every lap, but I always take extra care to make it smooth.

Although, I have an extended warrenty on the whole car and the service can be done anywhere. Maybe I should jam a little harder and get an independant garage to upgrade me to the 09 instead of an 07. Hmmmmm