Hello everyone! Purchased the subject truck a couple months ago and I am loving it. I have a a few things I have done and would like to do, but looking for some ideas or sources to help me plan.

New Interior and body is is great condition.
Plan on the drum to disc brake conversion...next upgrade
Not sure if I want to rebuild my 4.3L or Upgrade to a 350? Currently 134K miles, but not sure how it was cared for. Having some minor issues. EGR replaced 2 days ago for my loss of power/backfire trroubleshooting.
Transmission to upgrade or to not?