If I have a leak in my intake manifold end seal what will it cause? Oil leak? Vacuum leak? ETC?

 

Depending on where it is: vacuum, water, or exhaust (or any combination of the three).

- Eric

edit:
OH. I re-read and see that you specified END-seal.
That's different.

The end seals just seal the crankcase. If one is not sealed, it will essentially serve as an additional crankcase vent.
In accordance with Murphy's Law, this means that oil will come out of it instead of air going into it.

 

Thanks thats what I thought but I wanted to be sure it wouldnt pull vacuum some how. SO no oil no leak.