I have a 91 z28. My question is my distributor has the external coil. I have a distributor with the internal coil. Can I use it on my car. If so, how do i go about it??? I need detailed directions because i can not figure it out?? any help would be greatly appricated! I was thinking of using the external coil instesd of using the internal one on the extra unit i have but do not know how to go about it?