The one on the right is what came out of the car the threads are messed up.(might have been from hammering it straight). I've reinstalled it twice and it keeps bending so I bought the one on the left which is a bit shorter. Can I adjust the clutch pedal to make up the difference.

 

no, the adjustment is the height from the floor, with the clutch switch, and then the free play with the rod there.

you could use a bolt in there or threaded rod, its not super critical