My '68 GTX 440 stick 3.54 gear is less than impressive in terms of throttle response and low speed performance. I've experienced this in similar cars owned by friends. They are all basic garden variety 440s. Cam intake headers holleys 10 to 1 compression. The 340 stick cars I've owned seemed to have much better throttle response and low speed performance. THe cam in the GTX is a Comp. 305 Magnum. Used this cam in 440 A/body automatic. And it seemed to work much better. I'm wondering if it's cyl. pressure or duration related. Thought about dropping the intake duration down to 268 adv. and seeing if that makes a difference.Always degree the cams and try different ignition advance combinations.