The following specs were posted to the nets, and certainly aren't officially from Apple. Still, they jibe pretty much with what I've heard.
Model 6100/60 7100/66 8100/80 Processor PPC601 PPC601 PPC601 Speed 60 MHz 66 MHz 80 MHz Cache Optional Optional 256K standard Performance 25% faster 200% faster Native 2-4x 68040/33 than 6100/60 than 6100/60 Emulated fast 030-040 RAM 8 MB standard 8 MB standard 8 MB standard DRAM exp. 72 MB 136 MB 264 MB SIMM Slots 2 4 8 Expansion Slots One 7" NuBus 3 full size 3 full size NuBus NuBus Storage Standard 160 to 250 MB 250 to 500 MB 250 MB to 1 GB Floppy 1.4 MB w/DMA 1.4 MB w/DMA 1.4 MB w/DMA CD-ROM Optional Optional Optional Video DRAM video Standard Standard Standard VRAM 1 MB standard 2 MB standard VRAM exp. 2 MB 4 MB Standard Support 1 monitor 2 monitors 2 monitors SCSI High-speed High-speed High-speed asynch asynch asynch Dual SCSI channels Networking Ethernet on-board w/DMA channel, AAUI connector Other Built-ins 16-bit audio stereo in/out with DMA 2 serial ports-LocalTalk and GeoPort compatible, with DMA Channel Apple Desktop Bus (ADB for input devices) AV Models 6100/66AV, 7100/66AV, 8100/80AV Video-in NTSC, PAL, SECAM Video in resizable window Frame and video capture Video-out NTSC, PAL VRAM 2 MB standard, not expandable Interface S-video for video in/out Composite (RCA) adapters included Software System 7.1.2 Macintosh OS with AppleScript PC Exchange & QuickTime. PlainTalk text-to-speech and speech recognition software MS-DOS/Windows 3.1 with Insignia Solutions SoftWindows software with some models Other SIMMs 72-pin, 80 ns or faster, installed in pairs CD-ROM AppleCD 300i Power 100-240 volts, 50-60 Hz EnergyStar-compliant (7100/66, 8100/80) Logic Board Upgrades Models 6100/60 7100/66 8100/80 Includes 8 MB DRAM, same interface, audio, and video Expansion Same as applicable model Hard Drive 160 MB minimum recommended DRAM DRAM from upgraded system must be 72-pin, 80 ns or faster, installed in pairs Software System 7.1.2, AppleScript, PC Exchange, QuickTime AV Logic Board Upgrades Models 6100/60AV 7100/66AV 8100/80AV Includes Upgrade included 8 MB DRAM & same interfaces as applicable model Other Same expansion, HD, DRAM, and software specs as non-AV logic board upgrades Video-in NTSC, PAL, SECAM Video in resizable window Frame and video capture Video-out NTSC, PAL Interface S-video for video in/out Composite (RCA) adapters included Power Macintosh Upgrade Card Upgrade Card Processor PPC601 Speed Twice the clock speed of host motherboard Slot Motorola 68040 PDS Cache 1 MB AV technologies not supported. Host Macintosh Resources DRAM 8 MB min., uses DRAM on motherboard Interfaces None on card, uses host interfaces Expansion Requires NuBus slot in line with 040 PDS empty to install card Software System 7.1.2 with AppleScript, PC Exchange and QuickTime Supports booting Mac with host 040 or PPC601 Availability Concurrent with introduction of PowerMac