come to think of it kacey that is correct, i was thinking of another system that has the (flow divider), steering priority valve separate. On this truck the system handles that differently, all contained in the control valve itself.

now after looking in the troubleshooting guide for slow lift and tilt it does say to check and/or change the relief valve which you have done, but it also says that there could be the relief valve setting set too low, it should be set to relief at 2750psi. Also says there could be a faulty oring on relief valve body.
And last it says to check the control lever adjustment on the spool stroke, make sure you are getting a full stroke when pulling the lever.

also i would check the tank strainer (inside the tank), another section mentions this as a possibility if lifting speed is too slow.