windshield wiper wiring 3 speed vs 2 speed

[70 sublime]

My car and dash have the 2 speed windshield wiper set up in it so the dash has the 2 speed switch
Since I have put a six pack set up on the engine it has the bigger air filter box and I will have to swap to the 3 speed wiper motor for clearance

I am still putting my car together so the whole dash assembley is out of the car

Does anyone know what will need to be changed in the under dash wiring harness ?
Are all the wires there from the factory to run both set ups or will I need to add some wire ?

[Nacho-RT74]

On dash just the switch itself

At the firewall side, just the main linkage and the motor crank. Is like that on 3rd gens at least. Mostly sure 2nd gens too?

Aside the engine bay side harness, which is not a problem because the 3 speeds motor gets the harness already attached

[70 sublime]