The Nissan Path

Do the R51 PF, Frontier, Armada, & Titan truck all share the same frame just longer or shorter depending on application?

To my knowlege, the Titan & Armada are 'similar' chassis, but not exactly the same frame due to rear suspension location in relation to the front, and Armada has independent rear where Titan pickup has a solid rear axle.
Pathfinder, Frontier & Xterra are all 'similar' chassis to each other as well, but different for the same reasons as above. The Pathy/r51 is a smaller 'midsize' chassis than the Titan, so I'd think they are completely incompatible without some serious fabrication. I have seen a few posts of folks putting the Titan axles under thier Pathfinders, but having to custom make all the attaching hardware.

The V8 Pathfinder has the same front and rear differentials as the Armada. The front diff is also shared with both the Armada and Titan. The rear LCA’s are different on the Pathfinder and Armada, but the springs are interchangeable between the 2. The front differential is also the same, but the Titan and Armada have longer axle shafts.

The front suspension on the Frontier, Pathfinder and Xterra are VERY similar, if not identical. The Titan and Armada front suspensions are similar to each other, but not as similar to the X/Fronty/Pathy. But they are interchangeable as in a Titan Swap kit can be purchased, from basic to fairly radical. Coilovers, LCA/UCA’s, tie rod extensions and axle shafts can be used to add additional suspension travel for the X/Fronty/Pathy . This also makes the track 6” wider (3” per side), but adds quite a bit of suspension travel and also additional lift, depending on the kit itself.

I would be nice if the X/Fronty solid rear axle/leaf spring set-up could be used on the Pathy, few have tried, but none have actually succeeded.