"That's unnecessary. What you DO need to do is retorque the heads before a turbo installation. This advice is not something I dreamed up, but comes from one of the biggest heavy Ford Truck dealerships in the western states. Years ago many of the heavy fleet owners had new 7.3/6.9IDI's for their personal pickups and ATS turbos were all the rage at that time. The dealership shipped our heavy truck shop many parts so I phoned the foreman for an opinion on installing aftermarket turbos. They did not sell pickups, but he said they learned it was advisable to retorque heads on new Ford IDI's at about 30,000 miles. They had installed many ATS turbo kits, and he said it was especially necessary to retorque heads whenever installing a kit. I did so and took note that every one of my head bolts took up an additional 1/4-1/3 turn past their original position. It also cured the slight seepage at the rear of both heads which is common on these engines. Over the years, I figure if some of the self proclaimed shadetree "experts" that preach head studs on every forum had just retorqued the heads they never would have had gasket troubles. I've got 210,000 miles on my turbo kit and still on my original HD gskts. "
Repeat of a post regarding your question.