I'm uninstalling my Harland sharps not sure if I'm lining up pushrods correctly to the stock rockers .there tight and snug . Can I start truck when I'm done with covers off or will it make a mess I just need like 30 secs too sew if I missed something !

 

Tighten them all to spec, put VC's back on and be happy.

 

+1 - running with the valve covers off will create a real unnecessary mess all over your engine compartment - if you have any issues, you will know pretty quickly - just shut down the motor, remove the valve covers and re-check things. Another handy way to make valve cover removal easy is to glue the valve cover gasket to the cover or use studs in the heads to keep the valve cover gasket in the proper position.