Table schema:
CREATE TABLE table_name_18 (_number_of_constituency_votes INTEGER, _number_of_candidates VARCHAR, election VARCHAR, leader VARCHAR)

Question: What is the highest # Of Constituency Votes, when Election is before 1976, when Leader is Eisaku Satō, and when # Of Candidates is less than 328?
SQL: SELECT MAX(_number_of_constituency_votes) FROM table_name_18 WHERE election < 1976 AND leader = "eisaku satō" AND _number_of_candidates < 328