when i go to start the car it sounds like the starter just dosent have enought jucic to turn the motor over so i replaced starter that did not help replaced battery and both positive and negitive wires on the battery now here is the kicker when i put jumper cables on and let sit for 10 mins it will cranks over is this a bad ground or a short somewhere im lost its a 85 z28 with a 305 4bb quad jet stock plzz help.

It's possible that your alternator isnt charging the battery well. Try this: Get the other vehicle that you used as the "Jump-start" vehicle, Hook up the cables again with motor OFF. Wait 10 min and with "Jump" car still not running, try to start your car. If no change from before, then the problem is most likely not the battery or lack of amperage. You have already done almost everything I would normally tell you to do. (New battery, cables, starter, etc.) Did you use the same brand of starter? Check the back of the head and make sure your braided ground straps are intact. One way to test this is to connect one of your jumper cables from the negative (Ground) terminal to one of your accessory brackets on the motor, then try starting it again.

Let us know, and good luck!

i will try this in the morning thanks and i will let you know what happens

turned out to be the pig tail on the alternator was not conecting correctly