If this is the same problem that you had before new dist, may be different problem. Check plug wires, be sure going to correct cylinder. Check firing order, 302's have two different firing orders. Carb'd or injected? Look for vacumn leaks around manifold. Spray carb cleaner around manifold while idleing. If rpms go up, you have a leak.
15426378
Could be the ignition module. It's attached to the side of the distributor.
Imagine a straight line directly down from the center of the distributor. The oil pump is in the bottom of the engine and straight down from the distributor.
in the oil pan at the bottom the distributor drives the pump
take off the distributor cap see what you find.
On the distributor
its under your hood with the firing order and distributor order
Is there a picture of distributor cap firing order for 2003 ford f150 4.2 engine
1 - 5 - 3 - 6 - 2 - 4 The distributor rotor turns CLOCKWISE The marked # 1 position on the distributor cap faces AWAY from the engine
http://www.aa1car.com/library/ford_firing_orders.htm
It is on the block, between the coil and the distributor. Good luck findng a replacement.
I believe it should be close to the distributor at the front of the engine