RFlimited now recommend trying the receiver mod in 2 stages. The reason being when changing out both mixer and front end devices the blocking dynamic range undergoes a major improvement, it goes a little beyond -125dB. This is fine for the most severe cases of off frequency interference, one side affect, as you can imagine is it numbs the front end a little. Most people seem to prefer the modified version and we still achieve adjacent channel figures better than any RCI product without sacraficing any sens figures.Here is the new recommendation

Leave the original J-FET (J163) and the bias res(680 ohm) in circuit.
Replace the 3355 with MPS 5179 (pinout exactly the same) and add the 2k resistor per our sheet.
All other steps must be completed. And one other thing you might mention.
About 5% of all DF have an MCF in place of the ceramic filter. In order for this mod to work properly the 10.7 MCF must not be left in circuit, the 10.7 ceramic has to be installed to work properly. We have seen cases where we send out a kit and the customer complains that they see no improvement like we claim and it always come back to the fact that the MCF was not changed.