Girling said specifically not to split them. Lots of theories as to why, but no one seems to know for certain.
The theory I like is that the installed clamping force was critical for the bolts to remain in the region where they would not fatigue and break under repeated braking cycles. If you read through the ARP web site, they explain why bolt torque is a very inaccurate method of setting clamping force and why bolt stretch should be measured instead for rhythmically stressed joints (like con rods & perhaps brake calipers). Girling _might_ have felt the same way, and installed their bolts by stretch rather than by torque.