JD has and possibly still does manage the engine warranty on many of their machines. They buy engines from the manufacturers at lower prices this way and relabel JD.
My spin on your engine is that it is either an Intek or Pro series V twin that has a similar version of the Cyclonic Air Filtration System that is on B&S
Commercial Turf series engines. On the B&S website the parts manual is available in pdf form for the 44J600 series engines. The round air filter probably is a smaller diameter version of the commercial Turf engine filters. The filter is a different part number and uses the foam prefilter. The black plastic intake manifold on the Intek/Pro series engines and the single barrel carb indicate either an Intek or Pro series engine. They also changed the intake to cylinder head gaskets which were a problem on some engines with the plastic intake.
I strongly recommend that you use OEM oil and air filters and the oils that the operators manual recommends should you have a warranty situation happen.
I will likely never know if it's a Intek or Pro.
Wow! This is so cool! It's almost like a quest to find the Holy Grail. Everybody knows that there was one but nobody knows what it looked like!?
The dealer parts lookup system doesn't show your engine, but if I go to the briggs dealer only portal and do a search for you model number I can get the parts diagram and the owners manual as a PDF. So your engine hasn't been updated into the briggs interactive parts lookup system yet.
if you google your model number there is a little info there.