Hello, I have a stock 68 400 A.T. Recently had my carb rebuilt and have been tuning it. I have been able set my timing at 9B, idle speed at about 500, and fuel mixture at about 20in. I tired to get the most vacuum when adjusting the fuel mixture and the needle is able to stay fairly steady at 20in although I'm not sure how steady it should be, there is a slight noticeable movement in the needle but it never really reaches 21 or 19. I'm not too sure what else to look into to fix this bogging issue other than the accelerator pump which I have not yet adjusted because I'm not exactly sure how and what to achieve when adjusting it. I found this picture but I'm having a hard time understanding it, in particular "make sure fast idle cam follower lever is off steps of fast idle cam". Any help would be appreciated thanks.