I would advise the Grado for your preamp.
The 304, as well as most modern MC carts, are not a good match for your preamp.
In any case, I have found the 304 difficult to set-up properly with a number of preamps and phono stages.
The 103R has been a whole different story, very easy to set up and easily matching phono stages or Sowter step up transformers.
I guess the more expensive 304 is more picky in its companions!
The 304, as well as most modern MC carts, are not a good match for your preamp.
In any case, I have found the 304 difficult to set-up properly with a number of preamps and phono stages.
The 103R has been a whole different story, very easy to set up and easily matching phono stages or Sowter step up transformers.
I guess the more expensive 304 is more picky in its companions!