cool.
When i converted from propane to gas i noticed a slight decrease in temp
Natural Gas has nearly 1/2 the energy by volume of propane, so to get the same BTU you'd need to pump double the NG through the burner then the propane.
The way this is usually done is by changing the tiny orifices that feed the propane to the burners to ones with larger opening that feed more fuel volume per second.
Usually these replacement orifices are sized to get you the same final BTU, but sometimes they will be too small, for example if the gas line running to the grill has less flow then anticipated.
It may be possible to either adjust the flow rate with a screw under the burner knobs, or failing that drill out the orifices a touch bigger to make back the lost BTU.
My Nexgrill was able to be adjusted to higher flames with the knob adjusted.
Another benefit of NG is that it rises up instead of sinking like propane, so if you leave it running it'll disperse vs filling your yard/area with flammable gas.
disclaimer: gas is dangerous, get a pro to vet your plan before mucking around.