I pulled the zylinders today. After a little soft left and right pushing the crank, all zylinders were free and the engine cranked over... 6 of 8 Zylinders came out pretty easy but 2 are stuck on the second ring. Maybe I can remove them to the inner side of the engine?!
All parts have a "D" stamped in, even the connecting rod bearing... they show some uneven wear...
According to a list I found, the "D" stands for "1968", right?
Year Codes for B & RB Engines
A - 1965
B - 1966
C - 1967
D - 1968
E - 1969
F - 1970
G - 1971
H - 1972
J - 1973
P - 1960
R - 1961
S - 1962
T - 1963
V - 1964
4T - 1974
5T - 1975
6T - 1976
7T - 1977
8T - 1978