My heads are set up for PAC 1396 valve springs with 1.950 installed height. Here is PACs description:

Circle Track 1300 Series Valve Spring High Lift Roller Spring - damperless

Outside Diameter 1.574

Outer Spring ID 1.15

Inner Spring ID 0.826

Install Height 2

Load at Installed Height 260

Spring Open Height 1.2

Spring Open Load 690

Recommended Valve Lift 0.8

Spring Rate (lbs/in) 538

Coil Bind (max) 1.15