6.0 issues

[gottrucks]

Like the title says, I have been having some trouble intermittently with my 6.0 in my '01 2500HD. It is missing horribly right now. I have had misfire problems for a while now, previously, it set a trouble code p0308 for a #8 misfire. As it was intermittent, I would work on it, think I had it fixed only to have it come back later. So far, I have changed the plug, wire, coil, and injector. This truck sits around unused far too much. The miss is now back with a vengeance, and I have a p0300 code for a random multiple cylinder misfire. It may be worth noting that I have a very strong fuel smell at the exhaust. My fuel pressure does seem a bit low, but I wouldn't think I would have the unburned fuel smell if that were my issue. Any thoughts? If it is relevant, the battery did go bad, and I have just replaced it. Thanks in advance for any help!