Use bulkhead NA fittings like this one: http://store.summitracing.com/partde...5&autoview=sku

No weld, and in case down the road you no longer have turbo, you could cap it off using AN cap: http://store.summitracing.com/partde...5&autoview=sku

It is as good as weld. I'm doing the same way to my car.