need some help with mulidisc games

[MrCaine01]

okay for the past few days I've been trying to back up Marvel vs. capcom 2 (241 mb) onto a cd-rw but it's been giving me trouble SO i picked up godzilla for xbox and saw that it was only 944mb. I figure I'll save space and put them both onto the same dvd disc. Here's my question I got craxtion but I've been looking around for a tutorial and I can't find anything specific enough to make me feel confident that I don't waste a blank. So any help or imput would be appreicated by somebody that has done this before.