The red thing inside the spring appears to be an "air Lift" spring. Basically a plastic cylinder that you fill with compressed air to increase ride height and load carrying capacity. Very unusual to see them on a Terminator. If you look at the bottom side of the lower spring perch there should be a plastic air line there leading to an air valve hidden somewhere where you can adjust the pressure in the air springs.
I can't ID the springs but they are definitely progressive rate, normally used to increase load carrying ability. Does your car have a trailer hitch or something? Maybe the previous owner had a really fat girlfriend....lol!
Haha on the progressive spring comment. Thanks for the clues...I will look under the car later to see if I have a air fitting. It makes sense on what you said though.
I'm gonna guess Eibach for the spring. They use the progressive set up for ride comfort. People used to put air bags in the springs as a way of tuning for the track.
Those are drag bags, Eibach I believe. I have the same ones, they are to help eliminate wheel hop on launch. You have to play with the air pressure in each one to make it work right. There are posts on svt about it. Off the top of my head I want to say 7-8 on the drivers and 12 on the passenger..
eibach drag springs with an air bag to help with the weight transfer during the launch. the springs are soft and will squat when going from a dig. fill the bag with air and supposedly it helps put the power down. im guessing the bag is only on the passenger side?
unless you are doing alot of drag racing id swap them out to something more stable. if the previous owner installed all four then the fronts are also very soft and will feel very floaty