Which year Stang is the lightest from 79-93?

[Shelly87]

Hello everyone, first time poster here. I used to be a huge racer 10 years ago, and am now trying to get back into it.

I am looking at building a Mustang, years 79-93. I want to start with the lightest model possibly (years ago I raced an Impala, that slob weighed 4K+)

I would imagine the notches are the lightest, but I was not sure about the 79-86 stangs. If I was to get a pre 87 one, I would probably replace front and rear body parts with 87+ parts.

Thanks.