Trick Flow Heads: Conflicting Info on Mechanical Roller Spring Pressure

The heads with the 2.00” installed height 1.56” diameter springs are “designed” for SR cams.

The 1.55” spring could be suitable for a mild street roller, depending on the exact cam and application.

Measure what you actually have for installed height, and post all the cam specs.
There are numerous roller spring choices for the 1.90-1.95 range.


Edit - looks like you have a handle on the pressure vs rate situation.

The PAC 1225/1325 is pretty much what you’re looking for if you feel you need 650lbs open with .640 lift out of a 1.550 type spring.