I used to have a 69 LeMans with that motor. I had to drill holes through the head in each rocker arm stud and put pin through them because they were popping out after the rebuild. The rebuils was stock except for a mild cam. I stepped on it after my breaking in period was over and popped 3 rockers. So my Dad and I pinned all of them.
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Zumo
1968 C10 LWB
Dallas, Texas
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