Speedmaster sale. It started

What did you use to open it up some? An angle die grinder and short carbide bit? It seems like a tight fit to get any tooling in there.

I've already got a 'new' old 440source until and it's REALLY tight and with tiny water passages.
A combination of porting burrs, I have several flexible burrs.
I already had the burrs, so no expense there.