Narrowing torsion leaves?

[Millhouse]

I'm about to build up a 3" narrow beam and was wondering what's the best and correct way to narrow the torsion leaves?
What size drill should I use?
How do you mark where to put the new dimples?
I've been searching for a good "how to" guide for the past week but haven't really found one. I don't want to get this wrong.

If anyone can point me in the right direction that would be great.

Thanks in advance

 

[radish]

Build the beam up to the trailing arms with the center grub screw in place, you can then mark where the ends need to be cut off. Cut off the ends cut a groove in the ends of the leaves and put a bead of weld so they don't move.
For redrilling the dimples get a 12mm cobalt drill bit or 2 but to mark them drill the center out of an old grub screw with a 6mm and the you have a guide

Does this make sense?

 

[Clem]

When I got my (4") beam, Paul at T2D told me how much it all had to come in by in millimetres.
I cut the leaves down using a 1mm cutting disc in a grinder, and drilled the new dimples in a pillar drill. Measure twice etc etc.

 

[Millhouse]

Thanks for the replies.
Thanks radish, that does make sense. I'll order a couple of drill bits and have a go at it over the weekend