A good friend of mine runs a camero street car makes over 1000 to the wheels with a 9" with no problems. Another friend has a 70 chevelle 540" with big twins made 1470 H.p. to the wheels at sema, Full street trim including full interior, exhaust and mud flaps. car weighs 4000lbs and best run of 8.40's @169 mph. 9" ford lasted 3 years until it twisted the pinion off trying to beat his 8.40 pass he ran earlier in the day.