removing spark plug tubes from magnum heads and...
I had to use a pair of pliers to get the plug tubes off. I'd get some PB blast and hose them down with it.
Before you go working on them, you might check them over for cracks very carefully to see if they're even worth messing with. My magnum engine had only about 50K on it, and at least one of the heads was cracked between the valve seats.
It would pick your 318 up a lot to run with the Magnum heads. Especially if you had them milled a touch. You do have to have the pushrod holes machined a little bit or else they can jam up due to the angles with the flat tappet camshaft. Also, you need a Magnum specific intake if you don't already have one, or have someone drill the heads for both bolt patterns.
If you've got $600, you might try saving up a little and just buy some of these:
http://www.hughesengines.com/Index/...earch=4675&searchmode=partnumber&partid=25428
They've already got the LA bolt pattern, plus they don't crack like the Magnums, have better valves, good springs and flow more.
If you don't mind the Magnum bolt pattern, there's these also:
http://www.hughesengines.com/Index/...VhZHM=&searchmode=keyword&page=2&partid=25701
They're $100 cheaper:
You probably know this, but to run the Mags on your 318, you need different pushrods and oil through lifters.
Good Luck
Steve