Yeah, I was trying to get it to boost to 10 without it moving. I don't think the e-brake is good enough to hold it at 2800 RPM. I don't have three feet to be able to hold the brake down and slip the clutch while pushing on the accelerator. I might try doing that with a stick, maybe.
I also thought about the boost gauge hooked up to the coolant lines, a tee at the reservoir might be all I need.