vibration problem is owning me help!

[sleepin240]

OK so I have read tons of threads about vibration and none seem to cover my problem. I have a rb25 powered 95 240sx. I am using Mckinney mounts and driveshaft. The vibration is coming from the rear of the car, and becomes intense at 75-80 and slowly fades away the faster I go. My tires are freshly balanced as of today, and my alignment is brand spanking new as well. I am running adjustable rear uppers, and toe control arms. My subframe was clunking very bad, so I installed peak performance collars last night before my alignment today. Im also running z32 brakes front and rear, I jacked the car up and ran it in gear to get a look at things, and from what I can tell the driveshaft looks good, it looks to have no runout at all. The passenger side rear rotor appears to have a little warp to it as well. The subframe bushings are shot for sure, the collars are just easing the pain of the clunking. I have noticed that when driving the vibration is get worse under throttle, I can coast at 75-80 and its not nearly as pronounced. Could maybe the subframe be moving under load causing the vibration? I am stumped !!