If the only thing that you want is to make some laps, or run the car on the street, of course you can.. But it is not going to be fast if you use the right gear to keep the motor in safe running conditions. (Not only the overol weight is important) the movements parts are heavier than any 1/10 scale especially the tires and the axles.
If you manage to adapt the 540 motor can to 1/8 scale motor mount, (I don't think that they share the same bolt patern) You are also gonna have to use an adaptador for the motor shaft. (the 540 is some like 3 mm and the pinion for 1/8 are 5 mm). OFNA use to have that adaptor in the old garmin SCT that maybe you can use.

good look with you modification...