When Casey Kasem calls something a remake, he means something very specific and something that's probably not what you or I would think of when we use the word "remake." He means a new version of a song that has already appeared once in another version in the Top Forty.
For example, on American Top Forty from September 30, 1978, Casey mentioned that the week's countdown included five remakes, two of which were from the soundtrack to the film Sgt. Pepper's Lonely Hearts Club Band, Aerosmith's "Come Together" and Earth, Wind and Fire's "Got to Get You Into My Life." But he didn't include Robin Gibb's dreadful cover of "Oh, Darling," which is a remake by most people's standards. Shoot, it's a remake by anyone's standards but Casey's.
You may have noticed that the Sgt. Pepper's Lonely soundtrack thus placed three hits in the Top Forty at once. All three songs made it to the Top Twenty-Five, in fact, but the soundtrack record was considered an enormous flop. It shipped enough copies to reach the Top Five on the album charts, but most of the double LPs were returned. I'm pretty sure I've never even seen a copy.