If in doubt, go for the brutal option.
I tried scoring a block with an angle grinder and then using a bolster and club hammer and the 100mm block broke and the join on the 3/4 block was very ragged because of all the aggregate.
Went and hired a petrol powered stone cutter and it went through the block like a knife through (hard) butter. Looking at the cut face there were some really chunky bits of stone and I don't see any way that those would split cleanly with a bolster.
So noisy and dusty is the way to go.
Cheers
Dave R