Hey Jeffy,
I installed a 136 amp alternator, upgraded the big 3 wiring to 4 gauge, and popped in an Optima Yellow Top at the same time. I got the alt brand new for $100 from 'Penny Pincher Auto' in Phoenix, AZ and it came with a lifetime warranty. I can't remember the brand off the top of my head but I still have the packaging in a storage unit so I can check for you in the next week or two. I was also looking at the 160+ options and hoped to make a junkyard find, but this option ended up making the most sense at the time. I needed to upgrade because I'm running a 600w (rms) amp to drive 2 300w rms 10" subwoofers built into the backseat and a 1000w power inverter mounted under the dash, and it was making my headlights dim and flash at night and would drain the battery every couple weeks. The new one's worked perfectly for me for the past year-and-a-half since I installed it; no more dimming headlights, poor starts, or anything electrical related. I also tracked fuel mileage before and after. I installed the 4.0L TB at the same time as the amp, and the combination of the two resulted in a mere .2 mpg reduction afterwards, barely even worth mentioning. Hope that info helps, let me know if I can be more descriptive.
