DOES ANY ONE KNOW WHAT THE HORSEPOWER RATING WAS ON THE 390??

 

Actually, the HP rating depends on a LOT of things:
1)compression ratio- regular or premium gas required
2)intake- 2v or 4V intake? or something else?
3)cam grind-torque biased truck engine vs other
4)single exhaust or duals
5)cylinder heads -- valve size
6)SAE or net? They changed the rules...
How much horsepower is kind of like asking how big is much?
No offense intended, but you need to refine your question...too many variables.
tom

 

How about this: What year, and are we talking stock? Also, is it a car or truck engine?