Here is a full game hack which updates the graphics to ones pulled from Super Mario Bros. 3 and changes all the level layouts for a new game experience.
Super Mario Bros. (JU) (PRG0) [!].nes - GOODNES 3.14
CRC32: 3337EC46
MD5: 811B027EAF99C2DEF7B933C5208636DE
SHA-1: EA343F4E445A9050D4B4FBAC2C77D0693B1D0922