Don't need to patch the BIOS. Is the drive already partitioned or a new install? The BIOS should read the partition table right of the HDD if it is already set up.
If this is a new HDD install you still don't need to patch. Install the drive and use XBPartitioner to do the partition setup. You can define the G drive there if needed or set F to use 32K clusters, breaking the 250GB barrier. I've tested this cluster setting and it has worked fine, had good data up to the full 320GB of the HDD I installed with just F.
-Whoopin'