http://www.coinflation.com/ is where you can get all the current melt values. To answer your question though.. Today.. 1971-1976 Eisenhower Dollar (40% silver) $1.00 $4.50 each.
Even better, get buy quotes from mjpm.com, apmex.com, and tulving.com Those are real world values that someone is actually willing to pay for those coins.
PS. They don't list 40% IKE's on their website (not that I saw anyway), you would actually have to call, but they usually give you an instant quote right on the phone, you don't have to commit to selling them or anything.
Here is APMEX current buy/sell pricing for 40% silver coinage. Buy Price Sell Price $3,864.50 $4,114.50
