Vcc is about 11.3V, JFET Drain is about 10V with 2.2k resistor and JFET source is about 1.7V with 2.2k resistor
Something is off there just a little, your numbers would imply 0.59mA through the drain resistor, and 0.77mA through the source resistor.
I don't see any other DC paths, so I will assume that is just measurement error. If it is not just measurement error then that implies another DC current path somewhere which is not indicated in your schematics (or the resistor values are incorrect).
I wasn't able to freely manipulate Vsource
The source voltage is determined by the current through the source resistor (I*R). Since the gate is fixed at 0V, the voltage at the source sets the gate-source voltage (which is usually actually measured as the source-gate voltage, reference/negative terminal of your volt meter connected to the source terminal, i.e. 1.7V at the source and 0V at the gate would be referred to as -1.7V since the gate is more negative than the source).
You could increase the R term in the V=IR equation, but that will increase the difference in gate to source voltage, which will bias the JFET closer to cutoff, i.e. less current, which will decrease V.
I am referencing the Central Semi datasheet here:
Central Semi 2N4416 datasheet
Note in the electrical characteristics table on the first page that VGS(off) is listed as between 2.5V and 6.0V.
You have a measured drain-source voltage of 8.3V (with the caveat noted above that the values given are not physically possible exactly as described) and a gate to source voltage of 1.7V.
Looking on the electrical characteristics graphs on page 3 you can see in the top left graph that if the device has a VGS(off) value of 5V, then at 8V Vds and 1.7V Vgs the current would be about 7mA. 7mA across 2.2k Ohms would be 15V, so you know that does not match the device in your circuit.
The graph below that for a device with Vgs(off) of 1.2V would have 1.7V gate to source voltage off the graph to the bottom, since 1.7V is more than the cutoff voltage of a Vgs(off)=1.2V device (cutoff in that datasheet is defined as the voltage which causes device current to drop to 1nA).
You can hopefully see from the wildly different y-axis labels on those two graphs that it would be nearly impossible to have circuit components which give a specific voltage for any randomly picked 2N4416 device (since the same gate voltage could result in anywhere from under 1mA to over 10mA).
To get your circuit to work you either have to buy a large number of devices, and measure them all until you find one with the Vgs to current relationship you want, or you have to change the circuit so that the gate voltage can be adjusted to match the specific device you have.