On your truck the left side (driver's) cylinders are odd 1-3-5-7, the right side is even 2-4-6-8.
Small block firing order is what Goldie Driver said 1-8-4-3-6-5-7-2. In the order the distributor spins.
You do not need to get the engine at top dead center (TDC) to replace anything. Just leave the distributor installed and remove parts, make note of where the wires go and put them back in the same spot on the new cap. After you unbolt the module, use some brake cleaner on a rag to wipe off the old heat sink paste, apply the new stuff to the new module and bolt it is.
The coil is easy to put in when the cap is on the bench.
When removing the wires from spark plugs and distributor cap don't just yank them off. Wiggle them back and forth while pulling up. If you just rip them off you may, and most likely will, pull the terminal off the wire.
Some people will put masking tape numbers on the wires and remove the tape when done, some will use a sharpie, others just check each one to the cylinder. Do whatever is easiest. Don't worry, this is way simpler than what you just did.