I bought a Stroker I bought this for $3000 it's new as I was told I found out that 2 of the rods are a different weight.

The car starts fines drivable once I give it full throttle it vibrate in high rpm and then the oil pump gage drops and start turning off.

Do you think this is my problem am really disappointed because I got ripped off.

 

If you measured the rods that means you took it apart. LS motors are internally balanced so perhaps your motor is unbalanced and that is why it vibrates at higher rpm.

LS motors need to be blueprinted and balanced, oil pressure dropping is no good but that can be due to pump and pickup tube install.