Personally, the amount of work and misery is directly proportional to the tools you have, the moron who comes over to volunteer his help and does nothing but offer smarty-pants suggestions, and the ease of getting to the motor.
In a big block (390/406/427) ford you had to pull the head, same as a 327 chebbie or 389 poncho. You need a valve spring compressor. Since you have the head off, it may be time to examine the valve stems & seats looking for damage and or excessive wear. Since the heads are aluminum I am just assuming they have inserts for the valves to ride in so be sure they aren't falling out or scarred. You will need to replace the head gasket, probably the intake gasket, probably the exhaust gasket. Oh, a torque wrench.
Chipped, burnt, or otherwise not perfect valves you may want to replace. Stay with factory stuff.... If you want to get rid of burnt up carbon on the stems you will need protective glasses, a bench wire wheel, a smooth wheel, and a mild very very very mild abrasive. Carefully remove the carbon, gently polish smooth. Do the entire valve south of the carbon buildup line clear to the valve face. Avoid the bevel as that has to seal the combustion chamber. Be sure your oil return drain holes are clear. I always used to replace the clips aka locks that secured the valve stem into the retainers.
Sounds awful but is actual easy. I did this on a bunch of different FoMoCo engines and Chebby/Poncho junk.
I once rebuilt two heads and when I was done, I found 8 NEW seals. Sure enough, i had replaced 8 old with the 8 from the other side. That was when I stopped drinking PBR's while working.
