Rensim

So I'm currently working on and testing a largeish re-texture set of Criquette's various neighbourhood deco items so that they match CuriousB's road replacements, and something is starting to irk me a bit. I'm not sure if it's just me, but has anyone ever noticed that the road and trolly stuff sits a smidge above the ground? It's really only evident when playing a lot, where it hovers up to my sims' knees. The thing is I notice this about some maxis items as well, like the fire hydrant.

I'm not skilled in the ways of meshing, but I wonder if anyone out there might be able to fix this :/