inter cooler for 5-psi vortech

i was told that a 5psi charger is not enough to inter cool it wont provide the correct amount of boost is this true or will i see any gains

You can intercool any boost level, and there will be benefit. However, 5 psi is a low boost number, and an LT1 can usually run that amount of boost safely with no intercooler. So, yes, intercooling would help, but you're not really running enough boost to see a big benefit.