hey guys does anyone know if the 5.2 magnum head is the same as the 5.9 magnum head?

Yep

5.9 r/t head if your looking for more go

Look at the casting numbers If thier the same, they're the same

There are a couple of different castings of Magnum heads. But I'm not familiar with the years or applications. They can probably be used/mixed for street applications. But friends who race with them have said that there is one that flows a little better than the other.

To the OP: The difference in flow between all the heads is probably no more than the differrence between a factory valve job and a HP one. If one is racing a stock class, then the "natural" flow advantage of 2-3 cfm may be noticeable, since they are dealing in hundredths of a second ET.

R.