There is more to "34 degrees total timing" than just that number. Mechanical advance can be adjusted to come in at a specific RPM.
Vacuum advance can be modified as well. Initial timing plays in the formula as well.I am not going to pretend that I have any idea where your issue is or what to try, but 34 degrees total timing is pretty much the golden standard to get the most out of a V8 Chevrolet.
