Fuel i'd check the pressure check your fuel line for kinks buldging or anything else sometimes line goes bad or breaks on the inside and can glog very easy make sure the carb is functioning fully
Spark i woul check timing make sure the balancer hasn't slipped make sure all weights and such arefree in the distribotor check wires plugs for carbon tracing
Not to dull it down maybe i'll spark some old memories for aome to help with ideas
