You won't benefit as you will only break everything in the engine. Springs and pushrods are at the very least a must! The CRs are very tight in clearance between the cylinder and the rings which can spell out disaster. To prepare for this many guys (including me) will have their cylinders a little larger than stock so the rings have a better chance of not exploding with that much friction and movement. With only a turbo upgrade you are asking for big problems. However, Cummins specs tell us that the engine is rated for 4000rpms for 15 seconds - so you can decide for yourself on this one if you want to risk it or not.