I have never stripped a planetary. I like to put a 4 pinion front and rear. Servo u can modify. There is a factory HD input shaft in 440 6 pac cars and Hemi cars. They have a dallop of yellow paint on the splined end. My buddies 71 bee at 4100 pounds has never stripped a planetary or broke an input shaft. He runs a trans brake. 840hp and 780tq. Kim
