This is a "ROLLER CAMSHAFT PAC VALVE SPRING KIT" for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6. This is a Pac 1201-X Spring set.
OD Outer: 1.260
ID Outer: 0.860
Damper: Yes
ID Inner: 0.770
Installed Height (Valve Closed): 150 @ 1.750
Open Load (Valve Open): 460 @ 1.200
Spring Rate: 540
Max Coil Bind: 1.115
Max Lift: 0.550
