Hi guys...I have a 87 cutlass supreme with a swapped 350 rocket... I'm not sure what to ask but when I connect my negative battery terminal my car begins to squeak, and seems to lose power as well..I have and optimum red top battery and I upgraded the "big 3" on the alternator and still no luck. Any suggestions guys? Thanks

 

I'm not sure what answer... Are you connecting the Optima battery with the car running, Where is the squeak coming from, what is the big 3 that you upgraded?

 

Also, what do you mean by "losing power"? Is the engine output reduced, or is the voltage decreasing?

 

If there's a parasitic current draw on the battery remove fuses one at a time until the current draw goes away.