71 demon heater controls stiffness!

Anyone know the fix for stiff heater controls ? They always were stiff I pulled the dash for a complete rebuild and while they were out I cleaned the heater controls they were still a bit stiff but a bit better now reassemble and the top off/ heat/ defrost is just about unusable. Any kits to rebuild the cables seem fine the plastic guides had some minor cracks . Thanks

IMG_6364.jpeg