This is the same for the JD 790 and 990 and the 3005 and 4005 which were almost the same tractors 790/3005 and 990/4005. Apart from changes between the models in fuel pumps, Alternator output, and even engine displacement etc, they were all Yanmar through and through. I own a 990 late model so it has some of the parts that the 4005 has and everything is Yanmar made. The things that are not Yanmar made are the FEL and the BH and of course the canopy is JD made. I don't know if Yanmar mad the ROPS for these units, they are fixed and not fold-able. (when I purchased mine the previous owner had cut the ROPS in order for it to fit in his garage. I bought a new ROPS and mounted it.) The 990 used both a JD 430 and a JD 300CX with the later models. The 300CX is made in China. The 430 has about 150# more lifting power so I wish I had that extra lift. The 4005 only had the 300CX. I don't know where the 430 was made but my guess is that it was NA. The 8A and 8B BH are made by a company in NA, Ameriquip Corp, which I beleive makes all of the JD CUT BH's and others like Mahindra's BH as well.
https://www.amerequip.com/index.html