actually, most amps will operate to 10v nowadays, and many older ones that i have run down at 7v just because. the power supply ic's and some other components don't operate below 10v, so naturally, that is where tha amp stops working. well, to get that, you need an amp in the range of 2500rms, so when you drag it to 10, than all you will get out of it is hopefully 1/2 as much. sometimes, even less. buy a few, because the overworked power supplies are going to cook pretty regularly...... or here is an option- spend less money and get a bigger alt. heck, you can even stab a factory cadilac/olds alt that fits form your loal parts store, and then you have at least 115a on tap. a good battery, and you can not have to kill your truck running at the cusp of shutting the injectors off, not to mention weaker spark, which will make you foul the plugs some. anyways, the closest thing to what you want, being in the rms range you want, and real efficient at it that comes right to mind is my rf t5001bd @ 1ohm. 180 it's yers, but do yourself a favor and get like a 165a+ alt