Thanks, but not really. I just guess and then fool eveybody, it's more fun. Looking over your wish list, only 2 things come to mind: (1) How much power will you actually be utilizing from the 3500W inverter (continuous, not peak), and for what amount of average time? (2) This MRAPPER light kit, is that a constant on deal or a temp use remote spotlight type of thing? Find its power draw if you intend to have it on more than say 2 minutes continuous for example. Short term loads are completely disregarded, it is ok to lean on the batteries for that. Your radios are an example here. They use no current in listen mode, hampster on a wheel could power that, and really only punch power in transmit, and unless you are broadcasting bedtime stories, their brief pull can be ignored in an energy balance. Again, it is OK to ask the batteries to help. My favorite way of powering a hungry system is running twin conventional units. Kind of hard to package on the 250 accessory drive, but not impossible, especially if you acquire an A/C compressor mount kit, and just convert it to mount a second alternator, which is easy to do. Like a boat with twin engines, it will still get you home even if one fails. Just have 2 diagnostic LED's in the cab, one for each alt, that would tell you if one went out to lunch, otherwise you may not even know one failed. If you already have the 400A unit, use it if it fits, but it is probably heavier than 10 bowling balls, so make sure it is mounted well enough to lift the engine by, and don't count on it lasting forever unless you can feed it cool air. If you are going to really load it up, increase the idle speed during heavy electrical load to increase the alternator cooling fan airflow and at least try to get the voltage regulator switching on and off to reduce the duty cycle of the alternator field circuitry. If the volt gauge drops down at an idle, the alternator is at full field trying to keep up. Fresh batteries less than 5 years old and seldom been ran dead is step one of a solid system. It lessens the load on the alternator greatly, so that frees it up to run additional toys. It's kind of funny, we get into this stuff because it is fun and bigger is better, but when one does this as a career, then it is like "Hey, you don't really need all that to do what you want.". Try your 400A, consider diesel engine vibration when mounting that heavy of a unit, or get a 250 A/C bracket kit and use two Delco or Delco clones. Clones are $89 each, genuines are $385 each. LN alternators have pretty low quality, hence they win low bids. They are now owned by a Chinese washing machine motor company. They merged with Prestolite just prior in an attempt to stay afloat in the market. For an 8.3, it is easy to add a second alternator onto the factory serp drive. Sorry, writing from phone, not sure which engine, thread title says 250. No paragraph spacing either, oh well.
