i have a 98 sc300 that im currently swapping in a 1jz. when i disconnected the alternator on the 2j the clip stayed in the engine bay but the 1j's alternator clip goes back into its wiring harness. do i swap the alternators, leave them the way they are or could i splice the one that stayed in the car with the new one?

 

Top pic is the alternator thats on the 1jz the second is the one that stayed in the car

 

The top plug is a 3rd gen Supra Plug so its safe to say that is a Supra 1jz but not to worry get the harness extended by someone competent and it will be fine.
GL!