I have set valves cold, hot and running. tcleaderman has the best plan. Set cold with a bit more lash. Don't you love that? Book says .006 intake so add .005 and you get .011. Book says .013 exhaust. add .005 and you get .018. Easy. Start at TDC #1 use the "BB" on the flywheel and watch the valves on #1. set them both and then set all the valves that are all the way up. That will be six in total. Turn the engine until the "BB" comes up again. #6 will be at TDC and both valves will be up. Set both and the remaining 4 that will be up. Done! Start it let it get all the way up to temp and shut it off. Do it all again with out the added .005 and you should be perfect. Not hard. The feeler gauge should just drag when the adjustment is right. Snug down the lock nut about as tight as a spark plug 12 to 15 foot pounds and all should be good. That "lash" is the "take up clearance that allows the lifter to follow the cam and still allows the valve to set tight on the seat. Keeps the noise down, the compression up and lets the cam and lifter live a happy life. New motor with a new cam need a zinc additive to protect the cam and lifter for the first 20 minuets. After that you are good to run the oil of your choice. Yes it OK to run with the valve cover off to see that oil is getting to the rockers and flowing like it should. Put the valve cover on when you are done. If you are on a level surface and parked it won't make a big mess. If you have oil spray all over you have the rocker shaft up side down. And that is easy to fix. At least you will be able to see that all is good. No guessing when you can see it work. If I have missed anything some one will give us a shout and we will both be smarter. Works for me.

Steve H