1993 Chevy Truck intake, or some tbi related issue

Engine Performance problem
1993 Chevy Truck V8 Two Wheel Drive Automatic +- 30k miles

For around a year my truck has had a miss; I fixed the acceleration miss by replacing plug wires, but it still misses at idle speed. I have also replaced the fuel filter, fuel pump, spark plugs, distributor cap and rotor, and icm. Although it still misses; until a few months ago this is all it would do. Now the truck will randomly surge when accelerating; it doesnt surge severely, but it is annoying. What most people have told me is to check the intake and vacuum lines by spraying penatrant oil and listening for the surge. I really dont know where the vacuum lines are, but I havent heard anything when spraying the intake manifold gasket. I have also been told it may be the throttle position sensor (which cannot be removed without removing the tb according the to haynes repair manual)or the idle air control valve. If I start tossing in new parts it will soon get expensive so I would like an expert's opinion. My silverado has a jasper 350 with around 30k miles on it. From what people have told me, many of the exterior engine parts like water pump or tb unit are not replaced when replacing the engine. So this leads me to believe the problem may be something exterior, hopefully.