I have a 1978 FJ40 with stock 2F engine. My distributor is a "For USA/semi-transistorized" per the diagrams in the Toyota and Haynes repair manuals. This distributor has "Vacuum Retarder" with a vacuum line nipple on each side of the retarder diaphram. When I bought the truck, all of the pollution stuff was removed and these two lines were capped as well as the vacuum lines on the carb. The engine starts and runs fine, but when I accelerate, there is a pause in the power and then a surge at full pedal. I have recently replaced the plugs, coil and ignition wires. Questions: 1. I cannot find any diagrams in the manuals that I have available that show how to connect the vacuum lines. I have run a vacuum line from a vacuum nipple on the carb base to one side of the distributor "retarder", leaving the other vacuum nipple plugged, with no noticable improvement in performance. Switching the vacuum line to the other side of the retarder does not change anything. Does this distributor need a vacuum retard(advance) to operate properly? If so how can I make it work? 2. Is this distributor problem likely the cause of the "flat spot" in the engin power. 3. I also have a "parts" FJ40 of the same (1978) year. It has an Except for USA/Conventional" distributor with a vacuum retarder that has a single vacuum nipple on the outer side of the vacuum advance diaphram. Would I be better off using this distributor and connecting the retarder vacuum nipple to a vacuum nipple in the base of the carb. 4. Any other suggestions.