Effects of sealing a wastegate flange on a tubular manifold

[wilddog]

I've got the chance to pick up a nice tubular manifold. However, Im running an internally gated turbo and this manifold is flanged for an external wastegate. My question is, will there be any negative effects of sealing off the flange? I want to keep it in case I go external in the future. Im thinking it may cause a dead spot in the exhaust flow. But Im not sure

 

[01QuadDak]

I can't see of any considerable negative effects on exhaust flow. It'd be basically the same flow problems you would run into if you had an external gate on there, which would be minimal on a street car.