timing help

[69PonyRider]

ok heres the deal, the way that my cleveland is performing right now isnt what id like it to be and i think its got something to do with the timing. I have and MSD 6AL w/ Blaster 2 and distributor. I recently purchased the car and the engine shook way too much so i checked the timing and it was at 30 deg, and 650rpm's i set it to 25 and later found that its supposed to be set at 6, is this correct? it is currently at 6deg and idling at about 900rpms, i think it should be idling at around 650 for auto right? but it backfires too much so i left it at 900 rpms. The shaking stopped but it feels sluggish, it needs a lot of gas to get going and sometimes backfires at the carb. Im not sure about this timing thing my dad helps me out with all this but hes no expert either, so what should the timing be set at or how do i go about figuring the right setting. Im guessing that 6 deg is for stock ignition systems, it ran pretty good when at 30deg once it got going but it shook way too much. could the sluggishness be also a carb thing? ill see what i get from you guys then ill ask more things. thanks in advance.