Early on in this build, I committed myself to a LS swap. The 'commitment' part came in the form of ordering up parts for the swap including radiator, fuel system, and engine mounts. I even welded in the engine mounts for good measure (they are bolt-in versions, with a weld across the top). That was > 2 years ago.
Back on page 3 and 4 of this thread, I posted photos of the completed frame with the engine mounts welded in. Member GaJeep94YJ posted that I had the wrong mounts. GaJeep94YJ had a 79 Chief with LS swap (same frame, pass. drop as 77 Chief). He ordered direct from Novak and was shipped MMSJ-G3. For his install, "these mounts will push the engine too far to the passenger side and interfere with the pass drop differential." He ended up having to redo all the work and install the MMX-WG3.
Turns out he was right!
GaJeep94YJ did his install about same time as I welded in my mounts. We may both have fallen to an uniformed Novak staff member or a bit confusing catalog.
So if you have a 1980-forward FSJ, with a driver's side drop, then yes you go with the simplified bolt-in (recommended top weld) Novak # NMMSJ-G3.
But if you have a 60s to 70s FSJ, you go with MMX-WG3. The MMX-WG3 mounts are welded in only (they won't line up to OEM holes) and are more complex / components that the later model. The good thing about the MMX-WG3 mounts is that they are adjustable (even after welded-in), notably from passenger to driver side and up and down. Whether you have a passenger or driver's drop, you can slide the motor either way.
Time to cut out the mounts, clean up the frame again, and weld in the correct mounts.
This is with the MMSJ-G3 (80-forward) mounts; you can see its pushing the motor over to the passenger side:
033 by
Max Bouthillette, on Flickr
This is even with trimming the center housing bump stock mount to make room for the passenger manifold:
157 by
Max Bouthillette, on Flickr
It did have room on the driver side to shift over:
154 by
Max Bouthillette, on Flickr