Now I am not the best person to really explain this, but in simple terms the 140 amp alternator will probably NEVER supply 140 amps. It doesn't work like that. Essentially, electrical items suck. They call for the amps they want rather than get force fed amps. Think about a hose pipe. It has water coming out of the end. If you're really thirsty you could put your mouth around it and suck hard - getting more water than was coming out to start with. The point is that you don't supply amps, you consume them. Sorry to the spods if that's a rubbish analogy, but the fact is that the alternator would probably only ever supply 140 amps if you had the winch running, two flat batteries and your headlights on. Remember that 140amps would be running round the whole car if it were being PUSHED out. All you fuses would blow and your wires would melt. It's supply by demand if you like to the items that can take it.
What you should do is change your alternator charging cable though. Should you be in a position where you batteries call for big amps the OEM cable might be a point of resistance. It's a pretty weedy thing. I put some nice thick cable in there.