Misfire chase

Last summer, I put a remanufactured head in my '86 b2000. It took me a few months, and it sat for at least 6 weeks torn down while I was getting parts and waiting for a good weekend to do it. Since I got it back together, it randomly misfires constantly on all cylinders. It's running very rich - fluffy soot on the spark plugs and oxygen sensor. So, I'm going to take some time off work and dig in again soon. My plan is to attack carburetor, exhaust, vacuum lines, and distributor. From what I've read, that should just about cover the most common causes. Rock Auto lists rebuild kits for two different carbs - a Hitachi and a Nikki. Do I need to take it out and find a badge, or is there an easier way to identify which one to get? For the exhaust, I figure I'm just going to pay someone to build and put one on past the CC, since I don't have to tools or space for exhaust work. Vacuum lines I'll just mark when I take the carb out, and replace one at a time when it goes back in. Distributor, I'm replacing the rotor and cap and maybe the vacuum advance. What else should I do? Valve lash adjustment? I realized the other day that the feeler gauge I used left the valve adjustment a little loose, but from what I've read, loose valve lashes won't cause a misfire, and they aren't making any tapping noises. Retorque the head? I asked about this on another thread, but I'm wondering if this is necessary, given that the head bolts are torque to yield. I know that misfires can be nebulous, so I've just driven it sparingly and researched it. I'm at the point now, where I'm ready to start taking it apart and buying/rebuilding parts. Any advice is welcome.