Stroker Motor wont Rev pass 5200Rpm

The Motor won't spin pass 5k when in park either. With everything you guys have pointed out makes me lean toward the springs. This is an old build. I'm going to pull a spring and have it checked. Most likely replace them but not sure what I'll be upgrading them to.

Thanks for all the input I'll keep you guys up
Do you still live in Indio CA? If so, I would start by drving to IMM and asking them what they think.