LA 360 high idle

If you have verified that the choke is good. That there are no problems with the high idle. And that the curb idle is set properly. Then next I would:

Rebuild the carb. Break it down entirely. Soak everything in carb cleaner/acetone overnight. Being sure to remove any plastic parts of course. Blow carb cleaner through it (pressurized can type). Then blow compressed air through all the passages. Re-assemble. And follow AJ's guide to Transfer Port Synchronization to properly set it up for idle.