Yes, the case is a bit larger than our stock alternators. The offset mounting ears definitely helped it fit into nearly the same space as the stock one does though. I'm sure I removed it from an LS 400 although I did read the pn from it as installed from below with a mirror so it's quite possible I got a number wrong. Would everything else fit as described? If the pn is correct, could this be fit on a late 80's / early 90's LS 400? I just want to know exactly what it is. Also, I totally agree that installing higher output components in any sized case can be asking for trouble but I'll qualify that. Newer components can be redesigned to be somewhat more efficient and therefore not cause significantly more heat but only within reasonable limits. I would define reasonable here as 5 to at most 15 peak amps more in the same sized case. The heat generated is relative to current squared meaning that the increase in heat becomes much more problematic as specs are pushed more than a little and this will translate into much shorter life before major failure if indeed you're pulling much more amperage than stock. It's not uncommon for rebuilders to advertise as much as double the current replacement parts or nearly so. If you really need significantly more current, stay away from these. In some cases, newer cars have liquid cooled alternators to save weight and keep reasonable reliability. One thing that's changed from much older high output alternators (police cars, etc. from the 60's and 70's) is newer ones also tend to have higher output at low speeds which helps everything, especially lights dimming at idle. Older high output alternators were absolutely huge, weighed a ton and at idle, actually had less useful output than stock. I also agree that ND parts are very high quality and turning one in for its core value on a POS rebuild from most parts stores is just wrong. I often ask people that buy these POS parts what their free lifetime warranty costs them in time and frustration every few months. You'd all be surprised at the responses. Some get it but most have no idea what they've bought into even when it's pointed out that their original part lasted many years and the replacements much, much less. It used to be easy to repair starters, alternators, etc. as most parts stores stocked individual parts as well as complete units. Not so anymore. In many cases, most of these parts are only available to rebuilders. I have ordered some of these parts online but recently found that my local Napa store could get them as well if, I provided the part numbers. Do a google search for ND parts. I'll also pass along a useful bit of technical info on belt tension. I installed a high power stereo in my 85p when it was new and within a few months, had the front alternator bearing fail. I originally thought that the added current draw likely had caused the problem but it was actually that the factory belt tension was way too high as it lasted another 25 years without failing until the slip rings on the rotor wore out to the point that replacing the brushes wouldn't have helped. Does anyone think that revving the engine well past red line a bajillion times might have contributed to the problem? Just kidding! This is also why I considered the slightly larger pulley on the replacement a good thing. Note that these parts are available as well but slip ring replacement is not for the faint of heart. Anyway, what most people don't understand is that these belts are absolutely stable and that the metal parts expand and contract with temperature. Ask anyone that worked on Harley's when they changed to belt drive how many belts broke when the bike heated up before they adjusted to a different procedure from chain drive whether or not they new why! So I find that the best test of belt tension is just enough to prevent slip which will be more likely the colder it gets. If it slips when it's cold, a very slight increase in tension is indicated. Keep in mind about too much tension causing bearing failure though. It is possible to have a very small amount of slip without any noticeable noise so look for a very shiny belt. Used belts will be smoother and not as dull as new but definitely not shiny. In most cases, these ND alternators only need brush replacement about every 150k miles to remain serviceable. The other major cause of failure is improper jump starting causing failure of one or more of the diodes in the diode trio. I won't bother to go into details here but just mention that it's not a coincidence that alternators fail after jump starting. I'll second what others have said about clean connections, checking for corroded cables and that verifying grounds is extremely important. I always increase the size of the body grounds when electrical needs increase. It's important to know where every ground is as well so access to a TSRM is a must. Many folks have electrical gremlins that do not seem electrically related but can be solved by cleaning and / or upgrading a particular ground. Note that many newer vehicles use anodized connection parts (bolts, washers, etc.) and the connection point as well and that these connections should never require cleaning. They are anodized to prevent corrosion. They should be very tight though and if adding electrical loads, it's best to leave these connections alone and add one elsewhere if possible. I have replaced these bolts with a similarly anodized part that I'd call a stud bolt, i.e., like a bolt with a stud welded on top and added connections at the same place if any other option was really a pain. I'll emphasize here that if adding high power stereo stuff for example, keeping its connections separate makes them easy to check while leaving the others as is. We all know or should search for particular problem areas with our cars. Everything electronic depends on a stable voltage reference for proper operation and that reference is always ground. I'll also add a shameless plug for optima batteries as what everyone says is that they last longer than most vehicles they're in. I used to replace my battery about every four or five years but my optima is over ten and still going strong. One final point is that alternators are not designed to quickly charge dead or severely discharged batteries and that's why the charging wire is not as large as engineering would lead us to believe it should be. It serves as a sort of current limiter keeping the alternator from working too hard and this is also good for batteries. Hard fast charging should be avoided unless absolutely necessary so use a battery charger to charge batteries and leave the alternators job to keeping it that way! One final note is that all ND alternators with the same plug do not necessarily have the same type voltage regulator so without getting technical, the terminal call out types must match for the parts to be interchangeable. I hope this helps!
