I own a 1970 Toyota Land Cruiser fj40. I have owned this vehicle since 1970. Shortly after I purchased it I installed an AC Delco distributor with a mechanical or centrifugal advance and an AC Delco starter. It has the stock F engine. The issue that I am having with my Land Cruiser is that each time I come to a stop and take off it has a flat spot, hesitation or it stumbles when I go to take off. If I don’t feather the accelerator it will often times stumble, hesitate, backfire or kill on takeoff. I have read and attempted to make changes suggested in this forum. Nothing has changed this problem not even an improvement. If anyone knows or could direct me to a solution to this problem I would deeply appreciate it. Thank you very much...Oliver