69 Ghost

Guys I am not dragging but doing a first gen conversion. I got the car running yesterday with the 4th gen harness hooked up. I would like to use the alarm and some of the other stuff and convert it to a first gen. I had to bypass the bcm by grounding the wire to get it to start. Anybody know if it is possible to use the alarm system without the bcm or have any idea about everything the bcm controls? I am asking because if I have to I will do a strip job like this post but I am reluctant at this point in time because I want to use the wipers, cruse, lights, etc off the new system. Anything would help including the Alldata wiring. I have a Mitchels and it is complete but some things are not clear like the BCM.