Ran a compression test on my 84 l69. These are the numbers I came up with.
1 - 136/134 2 - 150/150
3 - 144/143 4 - 153/154
5 - 135/138 6 - 152/153
7 - 134/135 8 - 150/149

The even bank is quite nice. How about the odd one? What could be up with that one or is it not to bad?

Bryan

 

there should be no more than a 5% difference I think. my 83CFI that I just rebuilt has a average of 117 psi with a +/- of 3 psi.

 

How did you test the compresion? Was the throttle blocked fully open for the test? Was the battery fully charged? Does your compression tester screw in, or do you simply hold it against the spark plug hole?

The good news is that the number are consistent on each side. That would indicate good head gaskets, at least. The bad news is that there is a big discrepancy between the sides. Are both heads the same casting number?