|October 28, 2013 - Time to upgrade the valve springs.|
As you may recall, I'm converting an LS376/480 crate engine into an LS376/525. According to GM Performance, the differences are the ASA cam and "higher rate" valve springs. So I called GMPP and got the part number for the new springs: 12586484.
Looking for these springs, I've found they've been superseded by spring 12625033. Fair enough, JEGS even sells the cam and springs as a kit so I picked one up. This handy little Comp Cams tool lets me swap out the springs easily without pulling the heads off.