I can go to a part store website and put my truck in and it comes up with a list but they very from 600 cca to 850 and so on, I know I have to have a recessed battery, also there’s a aftermarket stereo system with a 200 watt amp for whatever that means, my battery won’t hold a charge if the truck sits for more then 24 hours so I figure time to break down and replace it but I can’t find the specs on it anywhere internet Haynes manual, I apologize if this seems like a stupid question I just don’t want to buy a battery that’s not enough, and at the same time would like to stay out of the $300 price range if possible

 

I always go with the biggest, meanest, battery that will physically fit.

Are you sure the battery is bad though? Going dead overnight may be pointing to something staying on, and drawing it down.

 

I recommend a couple of things. Get the battery you have fully charged up, and then have it load tested. Sometimes people will try to load test a weak one and of course it fails load test. I think the local parts store will do that for you - just make sure they fully charge first.
Second, test your electrical system for parasitic draw when the key off. Lots of instructions on youtube on how to do this.

 

it’s got a aftermarket sound system with a amp and 2 12 inch subwoofers, that I didn’t put in came with the truck, I wonder if that could be the cause I know how to check for parasitic draw I need to do it before I buy a battery I suppose

 

ok so I’m glad I didn’t buy a battery hooked my multimeter up to it it’s getting a 1 amp draw, I’m assuming the sound system I just figured the battery was bad since it came with the truck and the truck sat for a yearish before I got it from a dui impound, but looks like my battery might not be bad after all

 

I know you found the battery to not be the issue, but just for information, my '08 5.7 came with a 600 amp battery from the factory.

I do the same and fit the largest battery I can.