Hi, I've got a problem with my gearbox. It's a 727. The problem is, It won't change gear until I drive at a certain speed. It will not change from 1st to 2nd until i drive in 30 mph, and won't change to 3rd before I reach 45 mph. This is during normal driving. That makes me stuck in 2nd gear when cruising, and that makes high rpm's and a high fuel bill. The engine is a stock 340. The carb is a Edelbrock Preformer 750 vacum sec. I know the carb is a bit big, but I tried it on becouse it drank to much fuel with the 30 year old Carter C-4-AVS. Btw, It shifted beautifuly with the Carter. Maybe the kickdown linkage has something to do with this? Any ideas? the rear end is a 8-3/4 with 4.10 gears. It also still uses alot of fuel, 9,85 miles pr gallon last time i fueled. My brother's 69 mustang with a 400+ hp 351 windsor uses less.