RoTaRyBoYz

hey guys i'm planning on using a autometer speedo for my 1stgen with a t2 motor.....i have a few questiions for u guys that have done this mod........which type of gauge is easier to install & calibrate,mechanical or electrical?? how do i mount the sender into the tranny?? does it fit like stock in the tranny or do i have to modify the sender?? ........thanks for ur help