Is there any way to morph from one model to the other?
yep, blender uses so called relative vertex keys (RVK’s). check out the online documentation for details.
I tried RVK’s but i’t didn’t work
Well, you can’t morph one thing into the other if one has more vertices. So if you’re trying to morph a truck into, say, a frog, that’s going to be very difficult because you have to use the same number of vertices, and you have to keep the vertices in the same order. If you reallly wanted to do that, your best bet would be to start with all the vertices you need set up in the shape of a box, then set two keys and model one as one of your subjects, and then the other. This would also probably look kind of weird anyway because vertices would cross eachother, unless both objects were fairly similar. Hope this helps.
you have to have the same number of verts and stuff
essentially you must make one model, then insert a second key, and modify that one [by moving verts ONLY, no adding new faces, deleting faces, edge cuts… only moving verts] into your other mesh