Need help modding MACH 1

Ok i just got a mach1 from a freind and was wondering what kinds of mods to do. Im thinking of changing the gas to r507 or r404 but would like to know if i need to change the compessor,oil.ect. or can i just regas it also if i change the fans will it help any.
Any suggestions and opions on the please fell free to speak your mind
Thanks

Does anybody have any ideas

i have no experience, but http://www.vr-zone.com/index.cgi?i=716&s=1

Thanks alot crimedog the link is very helpfull