I really dont know why you need a ton of juice for the set up you have. Im running a DD M3a and C2C and with the car I own, with a 90 amp alt, and a die hard platinum, it doesn't dim the lights at all. I have my amp set to the subs rms rating of the sub and while just playing a test tone at 50 hz, my alt is only putting out 60 amps. When you listed all of the equipment in your last thread, you stated "the amplifiers are a Alpine PDX-F6 with two 30amp fuses and a PDX-M12 with four 25amp fuses." I doubt you would even see the current draw being close to the total potential of your amps. So I really think you are going a lil over kill on the power and batteries. Unless you are trying to go into spl comps where you will be clipping the hell out of the amp where it would need a lot more juice. Even though you may have set your amps with a DD1, that dont mean that everything you listen to will not clip. Usually when you are clipping, the voltage will drop and hence why your truck is trying to keep up? The only time I even see a drop in voltage is when my amp is clipping hard. I would try to ask your dealership whats up with the alt first before trying to add a ton of batteries you dont need.