89 OMC 4.3L Cobra

I am dealing with a 1989 4.3L Cobra in a Sunbird boat. Boat has had very little use over past 8-10 years, but is a one owner. When trying to get started for this season, the engine would not start. Found that the engine was not getting gas, and upon checking, found the whole fuel system was cruded up with a "crystalline" type substance. Replaced the fuel pump and all fuel lines, including the tank pick up.
Engine now runs, but does not idle well, and runs a little rough.
Considering changing points and condenser as next step. Any addition guidance would be appreciated. Thanks !

Have you also checked the anti-siphon valve on the tank? I would say a carb rebuild should be done. Make sure to check your fuel filter, choke, & flame arrestor, to see if they're working properly.

Carb may need a good cleaning. We'll check that. Thanks !