Overclock without BIOS options

[Synful Serenity]

G'day mates...I have a Soyo I845PE-ISA board with P4 2.66....Great board, except for the fact that it did NOT come with the Soyo combo features that allow you to adjust overclocking parameters. I'm pretty sure the PLL is adjustable, but there are no options for it, so I was wondering if a BIOS mod with MODBIN or the like is possible. I do have CPUFsb installed, but I'm afraid to use that since it overclocks everything including the poor ISA sound blasters and antiquated MPU401 for the Roland MT-32 (Long live Sierra games!). So my questions are:

1: Is a BIOS mod feasible for this, possibly involving splicing an existing part of another BIOS that controls the overclocking features for that particular PLL?

2: Is there a way to lock the PCI/ISA speeds with CPUFsb so the rest of the system can be OCed?

I would have gone with Abit, but this is the only board I know of with ISA slots so I can run King's Quest 1 at 2660MHz...