Rick Parker Rick 2 thoughts First just add a 1 inch spacer to the lighter springs in the car all ready and stay with them. The rear needs to stay flat on the road surface and not bounce around going over dips and uneven spots. If you go with the heavy springs either get the longer ones or again add the spacers to the spring. I run the stock ERA spring that came with the Jag rear. The car rides great on the street but bottoms out on the track. I added 1" spacers and stayed with the same springs. I am 240 lbs, also going on a diet
The car doesn't bottom out and the ride is still nice. When I drag race, the car squats and leaves nice, left for wheel just about off the ground, good wieght transfer for this racing. If you don't mind that floating ride, go with larger sway bars on the car front and rear that are adjustable. Take out any rubber bushing and go to hard plastic or aluminium ones. They will need more maintainance but tighter ride. Have you had the car wieghted and balanced? This is a good place to start. Alot of guys don't do this before wheel alignment is done. They measure the frame in 4 corners and when even number comes out they are done. My car was 82lbs right to left front with me in it. and 46 lbs rear. Reset the car with the balance correct and the car handles alot better. I am in the process of getting bigger sway bars for my car that are adjustable from ERA. Hope this helps Rick Lake