Met a guy at a car show last week that has some Buick parts for sale. The only 401 part he has is a 4453 carb that my info says is for a 66 401 with automatic trans.
He also has a ST 300 trans with no torque converter, a mild cam for a 300 and block and heads for a 300, which are disassembled and needing work. He also has a set of spinner wheel covers.
If you are interested in any of this, let me know and I'll get prices from him.
Chuck