[KimMG]

Did you check the oil level? Was the motor overheated in the aftermath of the collision?
Cause of the knock could just be pre-detonation. Now that you got the car together, do a tune-up. Check and if needed replace spark plugs, cap, rotor, plug wires, check timing. Vacuum leaks can cause stalling. A vacuum leak in the manifold can cause burned valves. If it is not knocking any more, I wouldn't worry. Sounds like all you need is a wheel alignment and you will be good to go.