It seems to be really accurate. At 260 seat originally and a normal initial loss of 25-30 all the intakes are in the 230-235 range which adds up. The real key is to calibrate it on a fresh engine. I considered the Moroso unit but I don't think they will clear the tall poly locks with a stud girdle. Maybe they make one but I didn't look to hard.
I absolutely considered shaft rockers. At the time I couldn't stomach another $1200.
I haven't found the girdle to be a headache adjusting valves. It fits really well and doesn't change the valve adjustment. On the flip side, I haven't been that thrilled with the consistency of the valve adjustment. Shaft rockers are definitely the way to go. When it's time to freshen her up, different heads may be part of the equation so I don't really want to make that investment right now. I'm at .660 lift. Tiny little big block cam.
http://www.jegs.com/p/JEGS-Performan...59829/10002/-1