Once you've removed the rivets, you can separate the front pump cover from the gears and rear housing.
The two red arrows here are inlet and outlet ports which can be enlarged. The outlet port is around 0.110" if memory serves me correctly. You can easily enlarge both holes to the 0.140"-0.160" range.
Flow will still be restricted by the 0.130" endcap in the FCA so there's no reason to go overboard here.
Obviously, you'll need to deburr the holes and clean everything up. You can use a 6-32 machine screw from any hardware store to bolt the pump back together if you don't have a rivet gun.
That should do it. Sit back and enjoy the fact that in under an hour you were able to perform the same modifications that some shops charge over $1100 to do.
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I think I got it all...
Enjoy: Nemo