i use a foredom, had it for 25 years so my part numbers won't help you.... and a mix of burrs, cartridge rolls and extensions to make them reach where I need em to. I port cylinder heads as well... Its cathartic until all the aluminum and fine cast iron starts to make me itchy....
Smaller cc domes or a thinner head gasket.
135 psi sounds perfect to me though, paying for race gas is so expensive and sometimes even finding it is a real pain.
Its not fast enough?