Hey there,
	I can't answer all the questions, but I can tell you there are four more bolts
 (exscuse me) more bolts under the sheet metal above the four under the rocker
 arms you saw.  I just went through major engine work to Bucksnort.  She is a
 '78 bus with a DP 1600.  I had  several problems including compression in 3
 and 4 of 25 and 130.  Burnt valve.  It does not take long to pull the motor
 and makes it much more plesant to remove the sheet metal which has to be
 removed to get at those bolts. (at least on the 10xx  1600)  
				Here's hoping you head is loose...(is that rude?)

      
					Bucksnort and Cliff