76 d100 a727 trans 8 1/4 rear with 3.55 slant 6......3rd gear medium load 2500-3000 rpm i feel a sort of pull like something slowing me down brakes arent dragging and tranny was just rebuilt. rpm drops only 100 or so very intermittent no pattern other than what was written. im kinda leaning towards a tourque (sp?) converter issue maybe its a 2500 stall been in there bout 10 years. also previous owner complained the truck doesnt move right away when first put into gear when cold but haven't had any issues.any takers?