For what it's worth, hacking the A3640 with a 68060 is kind of like sticking a V8 in a Fiat Uno - mostly pointless. The memory access on a 3640 is so slow that it's being throttled anyway even at 25MHz, in the same way as a V8 Uno with stock fuel system, brakes and drivetrain is still going to be slow.
You're more likely to get crashes with a V8 Uno, though, I'll give you that.
