I have a 305 that is pretty healthy. When it climbs past 3000-3500 it has a weird kicking feeling. Im not too sure on how to describe it. Like the tach doesnt jump but it has a slight buck to it. It was happening when i had my th350 and now with my 700r4. When it first happened i thought it was the road but it wasnt. I had .75 jets in my holley 750 and now i have .74's because i was running a little more rich than i wanted but that didnt change how the engine acts. Any ideas?