1. I can't move this, but this is the 4th Gen thread, so people with 03-09 Trucks will be around in here and may not know specifics about your model.
2. In general, no. I am not saying it is not possible, but usually you have to get at the bottom of the engine and to do this, it is easiest to pull the engine and disassemble it to get at the crankshaft.
If you don't own an engine puller, you can rent them. Honestly, on a 90's era V6; it wasn't that complicated to pull apart. I owned the v6 and it is TIGHT in that engine bay. I say rip it out, rebuild it (which you should do, if you are replacing the crank and are going to be in it).
Check for sludge. That engine was notorious for sludge.