I dont know if the alts from the late models interchange, or will bolt up. I know the SN 95 stangs V6 alts will work, you just have to grind a bit off the bracket to make it fit. You will need to upgrade your wiring too, to handle the increase in current that is possible with these alts. As far as measuring current draw while its on the car and running, I have a clamp on AC/DC ammeter. It cost me $100. PM me if you want more details or ask here for all to see. I have personally verified its accuracy and its much easier to use than other methods which involve installing shunts inline in the circuit.