Originally Posted by steelnc
Exactly. These motors lift heads with stock horsepower. Get a monitor first if you don't already and monitor your temps.
These motors lift heads because of jacked up cylinder pressure usually due to a ruptured egr cooler. Actually a custom tune can get you more power with less than stock cylinder pressure. Matt's SRL makes less than stock cylinder pressure and makes great power beside being stock head bolt friendly.
You are probably good to 420-430rwhp if you don't flog the living quap out of it.