174/177 supercharged small block, where to start?

Well chit. It might not be creating boost. I'd still double check with another boost gauge. Are you SURE you figured the drive ratio right?
I mean. I posted that spread sheet, I was going off what I had and followed the chart. I don’t think I’m wrong. We will find more out tomorrow when we do another run. I next day aired that 2.5” pulley to be delivered tomorrow so, I’m curious to see what happens with it. :-)