Alright, I have got the funding and decided to start my LQ4 to 408 build. I wanted to know where I needed to start. I have put together a spreadsheet on the cost and wanted to see what everyone thought. After a little reading, it sounds like the L92 heads aren't going to give me a huge advantage. My ultimate goal is the 408 with a whipple on top with about 10psi. In the spreadsheet when I show "Inclu." that means I get them with the heads or they are part of the rotating assembly. Also, rename the file to Silverado 408.xlsx . Any recommendations?