yes the idea is best done with the intake removed. first the obvious. buy the felpro HS7733PT15 and grab the set of intake bolts and two sets of head bolts from felpro that are mentioned. do not open them yet. be very careful to only buy those specific part numbers know matter where you get them. buy some cheap oil and filter for about 3 changes. drain oil and coolant. remove the entire manifold assembly, valve covers and due a inspection for other issues. replace filter and fill with oil and use an electric drill and oil priming tool to pump the new stuff manually until entirely mixed up and flowing all the way to the top of the valvetrain and a few minutes after that, drain and refill, do i the pumping again and give the engine a couple of turns as well to help flush out the bearings. then the process all over. use more oil supplies until it comes out clean. when it does do the head removal and continue on. only open the felpro stuff if you are going to use it so it is returnable if needed. if you have to replace the block you are only out the oil stuff. if you save the engine replace any needed components with felpro or delco/delphi stuff. the delco plugs are CR43TS. autolite 25's can be used as well. we can go from there. btw with the manifold removed get a engine shop to clean it out.
