Movie buffs & book fans. Manhunter vs. Red Dragon?

So years ago I watched Manhunter & then when Red Dragon came out I watched it in theaters & sais to myself "hey, this is the same movie as Manhunter." Manhunter was on Showtime today & I noticed a few things. They go to the killers house & kill him there, but in Red Dragon he escapes the house & the police have to decipher the last code Hannibal gave the killer. Its Det. Grahams address. The endings are quite different. Also, in Manhunter I dont remember any reference at all to the Red Dragon. My question is which one is more true to the book? Or is the books ending different from both? P.S. The guy who played the freaky killer in Manhunter was Frankenstein in "The Monster Squad" That doesnt relate to the question, just something I noticed.