TGV deletes are good for approx 2 whp on most LGT's. Reason for deleting is not power. Reason is to make room for larger turbos. Get the motors and sensors out of the way.
Using a phenolic spacer accomplishes much the same thing as making the housing out of plastic. Is far cheaper too.
If going from sidefeed to topfeed, a set of used TGV cores usually runs $200-$300.
They look nice. But are probably major overkill.