hammer time!

[Dave]

What turbo is that? depends on when it spools tbh, but in my experience I wouldnt bother with a wastegate at all. All my turbos have performed their best with having all exhaust flow past the turbine. I think your best bet for fitting that would be on the other manifold to be honest, it will move the coldside right down a bit. You may have to even angle it down more with the other one though, it is a bloody big housing, but the entrance to the hotside is so offset from the turbo so far it means it sticks out quite far... 4mm is fine, it will be limited by other things anyway