It is 40% Silver
maybehttp://www.coinflation.com/coins/1971-1974-1976-Silver-Eisenhower-Ike-Dollar-Value.htmlAll of the silver "Ike" coins were minted at the San Francisco Mint in 1971, 1972, 1973, 1974, and 1976. These coins were either uncirculated or proof.
"I'm begging you, read the preceding paragraph again. For the love of everything holy, read every word. If you typed "silver Eisenhower dollar value" in your search engine, you may end up here, but it does not mean your coin has any silver in it. Most Eisenhower dollars don't, especially if it's worn and circulated. The best way to distinguish the two versions is by weight. The copper-nickel version weighs 22.68 grams, the silver Ike dollar weighs 24.59 grams. Please visit the clad version of the Eisenhower Dollar page if you have a circulated, worn dollar."