My intake mount had come loose allowing the intake to hit the transmission case.
Vibration is still present under acceleration from 50ish+. This had disappeared once I had my tires rebalanced. Did a WOT run, heard the 'pop' and now:
On acceleration in 5th and 6th gears, haven't duplicated in lower gears.
On deceleration from 65-40mph with or without the clutch depressed.
Banking a left turn minimizes it, but still present.
Banking a right turn minimizes it, but not as much as to the left.
If the accelerator is released, the shake immediately stops.
Can only be felt in the steering, but resonates throughout the body.
Tie rods, ball joints, control arm bushings and bearings are tight, no play.
Rear engine mount is partially torn, but for the most part intact.
Both outer bearing gauges have minimal play, left side is worse.
Axles look to be OEM.
Intermediate shaft has ~3/8" side-to-side movement, but no up-and-down movement.
Brand new tires. Rebalanced and corrected the majority of my shake.
Two wheels are bent, but they are currently on the rear and both balanced out.
Passenger mount looks intact and free of damage (leaks).
Haven't checked the transmission mount yet.
Aftermarket replacement struts and shocks (15,000 miles) with OEM springs.
Not that anyone is going to read this, but if they do and have some suggestions...