The timing is off several degrees from the TDC. I think it needs to be adjusted, or the distributor needs to be reinstalled to align it.
Hello. It sounds like a new distributor has been installed and is misaligned, causing the timing to be off. The truck timing needs to be set to TDC, then the distributor needs to be reinstalled, and timing rechecked. This should be done by a certified technician, such as one from YourMechanic.
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