Those lifters are pitted pretty bad. They'll ruin the cam lobes is used. If your others aren't pitted, scratched,cracked or showing any other damage you can reuse them but definitely replace those 4. How does the corresponding cam lobes look?
Lifters are somewhat easy to replace in truck but the cam ain't.
I like the shade of blue your using on your engine, what brand/color is it?
Dave
