If there is that much stuff up in the lifter valley, I would hate to see what is down in the oil pan as well as the throughout the rest of the block. The best thing to do would be to take the engine out, disassemble it, and hot tank the block. If this isn't an option, make sure you change the oil after you clean the lifter valley. Some of that stuff is bound to fall down the oil return holes, not to mention any anti-freeze that probably found it's way down to the oil pan when you took the lower intake off.