I'm interested, but have no input. I imagine there's a chunk more like me.
I've got a similar rig, and a similar desire for more power (like most of us), and a similar need to focus on minimizing cost. My plan has been to swap in a 6.0 that I have in a donor truck, but I'm possibly going to just fix the donor truck and drive it again. If I do that, I'm back to the TBI 350 and possibly VERY interested in what the best options are, along with costs and benefits. I know I can double the HP with the 6.0, especially if I add a little cam, but no more than I drive it, the reliability and longevity really aren't that big of a deal. If I get my drivability fixed on the TBI and gain a little power (I've got a dead spot that I haven't diagnosed yet, probably something simple but it hasn't mattered much yet), that might just be good enough to run for a while. So in short, keep us posted on what you do!