Sorry, don't mean to thread jack, but I'm having almost the exact same issues. Very low/rough idle when warm, its only died on me once though. When I drive at freeway speeds, the truck will slowly start to lose power and start to decelerate. I have to floor it to get the power back. This is a...
Looking back, I wish I would have put a set of vortec heads on mine and maybe a roller cam. When I was rebuilding my engine I was on a tight budget and a quick turnaround. But even without those, the Whipple really woke it up.
Can't say that I've had the same problem on my 94. I know my radio unit has gotten wonky before. I've just taken apart the bezel and removed the unit and used an air duster to clean the unit and the connectors. Maybe try that?
IIRC, when I rebuilt my engine at 205k miles (same year as you), the timing chain and sprocket still looked good. Thankfully you don't have to worry about a chain and sprocket as much as you do a timing belt. I'd say if your truck is running fine with no stumbling, misfires etc. you should be...
You definitely need to get the truck retuned with the smaller pulley. Fueling requirements might change. Also, I don't think those kits were intercooled, correct? Heat is the enemy. Once you get out of the 5-6psi safe range, you risk higher IAT's which could lead to some detonation. Water/meth...