Vehicle shake on acceleration

[prwdmd]

My 01 4.4 w/ 110k miles, has recently developed a noticeable shake, but only when I accelerate. Feel the shake mainly in front end, but also in gas pedal and floor/seat. Definitely not a tire balance issue. I'm in the process of replacing my suspension components (halfway finished), but I've never had this happen before and it kind of worries me. I notice it at speeds of 30mph +, but mainly on the highway. If I baby the gas, then it doesn't happen, only on moderate to hard acceleration. Has anyone had this happen or have an idea of what it could be? Thanks.


01 BMW 4.4i sport
05 Porsche Carrera S