The plate thickness is driven by the ratio. The 4:1 is around 3/8" whereas the 6:1 is around 2+". The "angle" created by moving the pushrod up the pedal arm creates a down range effect of requiring a thicker plate. So, the 5:1 plate will probably be around 1"+. The MC will be shifted towards the rightside of the car and moved upwards. The pushrod lenght remains the same. I think you solved the issue relative to the pedal arm. It's either splicing one or having a customer one made.