2001 F 150 4.2 V 6 When I place shift to drive shakes badly and dies What?

No codes? No CEL? No indicators of faults of any kind? We need this info.

Engine shaking is typically indicative of a misfiring cylinder, which would likely give you a "P030x" code. x indicating the cylinder number. If it is a misfiring cylinder, there will likely be other fault codes as well such as O2 sensors, MAF sensor etc.

Check your spark plugs, idle the truck, and one by one, pull the plug wires off the plugs to see if they're firing(arcing to nearby metal), and if they affect the idle quality. When you find the cylinder that alters the idle the LEAST, that's probably your problem cylinder. Also inspect the plug wires for cracks in the insulation, especially near the boots at the ends. And obviously, if the spark plugs are bad, replace them, they're $3 apeice.

And don't forget to check your fuel pump. That CAN cause these issues, though it seems unlikely if it only dies in gear.

So it starts up and it idles ok?. Is it ok when you rev the engine a little bit? If so I suspect the shaking is caused by a bad motor mount and/or transmission mount. Next I would check out the fuel filter and fuel pump. Could be enough fuel when at idle but not enough to keep engine running. Is the tank low on fuel and do you run it low on fuel often? Fuel pumps now are generally located in the tank and are cooled by the gasoline around them. Running a tank low allows the pump to heat up and wear out faster, although at 12 years that is a decent life.

If you have individual gear clutches in your transmission! thin/low viscosity trans oil could cause a more violent clutch action which possibly could overwhelm the engine at idle, drain thoroughly and replace the trans oil, Or pour it through a spray paint viscosity cup very cheap to buy or make your own, and compare with new oil.

To make your own viscosity cup!: use any plastic vessel 1/2 or 1 Qt and drill a 1/8" hole at the bottom near to the edge, fill with any accurately measured level of the oil in question whilst holding your finger over the hole! and then release the finger whilst timing how long it takes to empty to a broken stream of flow, and do the same with the Control sample (new oil) if vastly different then replace with new oil.