For vehicles of unspecified weight (under 3,400 lbs. total)
Progressive design reduces rate of compression, making it less likely for vehicle to "drive up" on the tire during violent wheel stands — as the vehicle pitch rotates the weight to the rear wheels, this compresses the spring making it more conductive to lifting the front end
Progressive springs compensate for added rear weight in Street Rods and Pro-street Cars using a back seat
Sold in pairs
For Front Springs see Moroso Trick Springs on the Moroso section of this website