**600hp sbm block limit? Or is it bs!!**

Bad *** build my man.
Thanks. My goal with that build was to never drag race. Light auto-cross but mostly just for blasting down the interstate with a TKO in your right hand and 3.55's in the rear. WOW! The whole car needs a redo. I left many things undone and eventually put the car away. A shop building is coming so in +/- 2 years we'll tear into it again.
With all that you said being great insight, also consider that getting to 600+ with power adders is not the same as all motor. Power adders make power as a result of power. I believe that is easier on the hardware than N/A at 600+ hp. And talk about frequency, not just duty cycles but harmonics. I don't know but even the whole driveline needs to be dialed with minimal NVH. Bellhousing dialed. On and on.
Cross every “T” & dot every “I” for sure. Then again, same for a racing engine.
As with power adders it's continual development. In 2008 The Supercharger Store was my source for everything Procharger. I worked with Hughes Engines because they had the most experience with Procharged LA engines at the time. It worked great for '08 but now for round two I will have things that weren't even a thing. EFI with timing retard and boost referenced? Smaller more efficient and cost friendly intercoolers, .... The thought of twin turbos has entered my mind as well, but now we're just chasing rabbits.
STS Releases Twin Turbo Rear Mount Multi-Fit Kits!