This guy has a wealth of info for the Amiga 3000 desktops
http://homepages.ihug.co.nz/~miles.j/amiga.html#SOFTbasically follow his recommendation for Softkicking A3000
>quote<
When installing a new boot drive in a 3000 with the original "boot ROMs", to get the 3000 to softkick kickstart, the disk must be called wb_2.x in hard drive toolbox and the drive set to FFS with out DC or international checked. Your KickStart image should be in DEVS: This is because V.36 boot roms boot the machine and look for a hard drive called wb_2.x to find a kickstart 2.x or 3.x rom image then reboot using the hard drive kickstart. Note that if you have V.36 bootroms the A3640 040 (and any other 040 or 060) card will not work, the machine will not even boot. The kickstart image for the 3000 must be for a 3000 to work properly as must "real" kickstart roms. ROMs from other AMiGAs do not support A3000 SCSI or floppy disk drives and so are not much use!
>end quote<
If you follow this you should be ok
Azryl