Will my CompCam 981 springs hold up with my LT4 hotcam? I'm running 1.6 rockers, new valves and the valve seats have been machined. The heads have been in the machine shop and got a bunch of things done, I just want to make sure these springs will work. It's for a TPI motor.

 

The .525" net lifts are getting close to the limits of 981 springs. If the installed height is at least 1.710" you should get by, but the springs are going to run hot. Right around the half-inch lift range is where larger diameter sorings should be considered. It's your call, but if the springs already have some mileage, you might have a reliability question.

 

Springs have never been used, just installed.