LT1 ignition questions ???

My 94 Caprice (150K) no longer wants to start in wet weather. First I checked to be sure it was getting fuel: A-ok. Next, I checked for spark: intermittent at best. So, after changing plugs and wires (what a bitch), I figured that would solve the problem. NOT! So, after asking around, the verdict was to replace the Opti-spark distributor (another bitch, and EXPENSIVE too). My main question is, should I also replace the vacuum harness and the coil? I live in Chicago and I want to get this done BEFORE the snow comes. Anybody got a clue?

Try the coil wire and/or the coil amplifier.