Smoke and compression test results

ok as some of you may know my tuck started smoking a week or two ago so i done a compression test today and here are the results
dry test
#1 172
#2 168
#3 125
#4 145
and the wet test
#1 170
#2 155
#3 125
#4 145
Here are pics of the spark plugs #1 Thru #4 left to right

#1

#2

#3

#4


Can anyone help me with where to go from here with these results

Does any one have any suggestions on where to start from the knowledge i have i can see the problems don1t seem to be in the rings but what all in the head could be bad and also what could be causing #3 & #4 to be so low especially #3