If you've got the standard battery it'll deliver around 700CCA so it's just fine. A suitable (not too expensive) upgrade is a 910CCA from Century Batteries.
Your alternator produces 150A? That's handy. Standard D40 produces 130A, so yours is going to do rather well.
As for starting amps (if you're curious), these diesels draw around 500 to 550 amps to turn over.