Here is the answer! Had the same issue and had a heck of a time finding it. Jenn-Air customer service was useless.
The service manual and install instructions can be currently found at:http://www.abt.com/product/20134/Jenn-Air-JDS9860AAP.html
The range originally came with two orifices #53 (0.0520 inch diameter) on the left side under the grill and two orifices #55 (0.0595 inch diameter) on the right side under the sealed burners. Jenn-Air does not sell these sizes. Can not be found
When you look up replacement parts online you will find part number 74009472
You will need to purchase 4 of these.
What is not widely publicized and even Jenn-Air customer service seems not to realize is that this replacement is a #54 orifice. They split the difference.
The rest of the conversion instructions are located in the install instruction on page 15 (inverting the regulator cap and adjusting the flame).
Good luck and pass this info on!