4D56 alternator: just a heads up, if you have it out, I'd at the very least put new seals/o-rings in it, where the vacuum pump attaches to it. If these seals fail, it gives the alternator a very unnecessary bath with oil, which makes it hesitant to give you all that new juice. (Mine happened in January, before I built a garage, when it was snowing heavy enough to cover my tools in the time it took me to remove the alternator bolts.)

You DIY diesel guys are probably very aware of this, but just in case it gets overlooked in the excitement of all that diesel smoke... <img src="/forums/images/graemlins/drunk.gif" alt="" />