In that regard the stinger is already at 20psi on a motor not known for its longevity, best figures with ECU map outside emissions, best torque management yields no better than OTR, headers and tune. In WangerShawspeak think W375 other brand 385 and that will pip a tuned Swinger with CAI, decatted etc. Following Wanger jargon, W407 trounces it in every sense.
In other words (like plain English without the brand bullshit) full bolt ons, mild cam and tune beats highly stressed strung-out fully sick Lambda II gerlytruck motor every day of the week.
The next level of switching turbos to get more, well there’s high compression and stroker. You know, Matching same effective displacement as a stock Swinger.