Use FamiRom. Couldn't live without it.
http://nintendoage.com/forum/mess...
The game is a NROM it seems. Id use a nrom 256 or cnrom. Maybe nrom 128 didnt really look into it much.
http://bootgod.dyndns.org:7777/pr...
Make sure when you split the rom that they are the same size the eproms your using.
John Riggs has vids on repros. Other sites too just Google.