Would 060 @ 100MHZ work

[Karlos]

It would work fine, just not at 100MHz. It's not the 68060 itself that is the problem but the rest of the logic on the board (not to mention the memory) would struggle to keep up. The fastest speeds I've heard of are around 80MHz for 68060 cards and only some were stable at that speed.

[Karlos]

80MHz has been done, not sure about higher clockrates.

Are there any modification I could do (or have someone else do!) thta could allow it to run at 100MHz?

For that kind of speed, you'd really want an SDRAM based system like the CT60 (for the atari falcon).

[Karlos]

Not really. It gets a very fast CPU board, but that's connected to a dire motherboard design with a 16-bit wide bus that made the original 68030 suffer, let alone the beast of a CPU they grafted into it :-D