The size of the bypass hole regulates the total amount of boost. The bigger the hole the less boost the turbo builds because more of the exhaust is bypassing the Turbo. You can install waste gates between the manifolds & the turbo to limit boost. I had a dial on my dash that I could use to crank boost down to a min of 5psi or a max of 15psi. Waste gates also let you build boost sooner and then start bypassing to keep the boost at the preset amount. The determining factor as to how much boost is determined by when the motor goes into detentation. When detonation starts the motor becomes a boat anchor real quick. Do you know what the static compression is? The lower the static compression the more boost you can run.

I have not dug into finding out the static compression yet.
However I need to correct myself on the cubic inches it is not
468 it is actually 511 cubic inches. The heads are worked 990's with 2.20 & 1.90 valves. Later, Scott

Nice 28 ,I hope there are more like that around it is exactly what I am looking for but with a TRS or alpha. Good luck with the project.

Hey Scott,

I sent you an email.

-Al