What heads you are using will dictate whether you need an offset lifer or not. Regular GN1s do not need an offset lifter. GN1Rs can be made to work without an offset lifter, but an offset makes it a lot easier. Honestly, if your build is based on a Stage II block. It is pretty much all custom from there. I have 4 Stage II blocks. I swear that nothing seems to be the same on the 3 that i have messed with! Of coarse, they all have different set ups. They have all had that WTF! moment when I ran into something I wasn't expecting.