Regarding the oil pump seal, do you know if it has ever been done before? If it is original, I'd be surprised if it wasn't leaking a little bit. If you decide to do it, the screws on the cover are easy to strip, so watch some of the OTRAMM or other videos on how to remove them carefully. This job also requires removal of the harmonic balancer, which is also a pain due to the torque involved and the need for large cheater bars. I think if I had no oil leaking on the front of the engine, I'd be tempted to avoid these items, since they don't seem to fail catastrophically.
For the throttle body de-carboning, you'd also want to remove and clean the upper intake plenum as well. This isn't too hard to remove if you lay under the truck with about 2 feet of socket wrench extension to loosen the nuts from underneath.
Honestly, I don't know if the oil pump seal has been done but in looking around the area, I can't see any obvious signs of leakage. In fact, around the valve cover gasket, I see no leakage that's readily apparent. Some from the distributor, indicating the seal needs to be replaced, whichnb I've already purchased...it's just waiting to be installed.
If there's no apparent leakage around the oil pump seal from a cursory look, and a more detailed one once I get into the R/R of other parts, I'll most likely leave it...with that much involvement, I don't feel that my skills are up to par enough to deal with it. When it goes into the shop for a look over, I'll ask them about it.
Thanks for the advise on that!
I'll also remove the plenum...thanks!
I'll post some engine bay pics this weekend, or tomorrow at the earliest.