I a excellent set of erson#3200 drop in springs for a lt1,all you need is to use new locks.The springs I have are a whole lot better than the lt4 springs.specs are 120lbs @ 1.78 stock height/310lbs @ 1.20 with a 340lb rate and good to .570 lift ($60 )to your door.I have a friend using these on his race car with a.580 lift solid roller,and turns around 6700rpm all the time.

 

goes in the FS section.