When im driving down the road it will read normal at 13 but when i come to a stop it will begin to dip and go down to about 9 and the engine seems to lope a lil bit. I just put a brand new alternator in and had the battery checked they hooked it up n said it had enough of the cold cranking amps. Is there something else that could be causing this?

 

Dirty/corroded connections between the battery & starter, block or alt or cables that are starting to feel thier age. I had a 76 suburban that did something similar to your car. I replaced the batt cables (corrosion on the actual wire around the termals tipped me off) and it fixed it. I cut the insulation on the old (original) cables and they were green w/corrosion all the way through.
Not saying this matches your problem or is the solution (since it's just my opinion) but, clean connections & good cables promote a healty charging system.

 

I tried looking for new cables and connetors for sale on the different dealers like summit and jegs. The majority of the kits came with like 15' of red cable for the + side and only 3' of black for negative. Im not quite sure how the charging system looks but wouldnt i need more then 3 feet of the - ? Do the cables just run from the battery to the starter? I looked at the alt cable connection and there wasnt any signs of corrosion, on the connectors to the battery there was a little bit of corrosion but nothin significant. Also does anyone know where the ground straps are located? i heard these can cause a voltage drop.

 

Those standard guages are not accurate, and some seem to give an unexplained low reading when the car is stopped but the engine still running and the transmission in drive. You need to check the voltage with an accurate meter, before doing anything expensive.

You only need a hint of corrosion between the connectors and the battery terminal for enough resistance to cause a problem.

The body connection can corrode and cause a lot of resistance. Also the positive supply terminal on the alternator can be loose.

If the alternator is new, check the cable connector is tight. Also the belts and all the bolts are tight.

There is an earth strap between the engine and body at the the rear of the engine near the distributer. Again check the connections and the strap, as they are made of woven wire, and that can fray and break.

Finally check the connections to the starter and solenoid are OK. That is most of the circuit covered.

Those long red cables are for the high power sterio amps, located in the trunk, you can get proper ones for the battery to ground etc., made up at NAPA.

 

I just fixed the same problem that you have, mine was a bad connection on the charge wire from the alternator, i put a new connection on and it works great now