I know what he does and have no problem with it. the problem is when he first came on here there was some claim to adding horse power by a simple correction. and my offer still stands just like the one with our newly found carb guru. you make claim back it up. I will still wager that he can correct mine from where they are now and you would see little gain if any. I set mine up just like have done for nearly 40 years and I get more than my fair share of passes. I know the geometry is off it's always been off. long before correction part were available.
If your current rocker arm set up has a very wide sweep the mechanical action input on the adjuster side is not making efficient use on the output side and you have loss of lift at the valve. The max lift may not be impacted much but the all important low and mid lift (where the valve spends the majority of the time) will have less valve lift, slower rate of lift, and adversely flow potential. Think of it like buying a fast ramp roller cam only to and find out you are missing out on performance potential because the rocker is sweeping out some instead of opening the valve.
Will the correction make power?
If your geometry is off (wide sweep) in theory yes it will make more power.
Can an amount be guaranteed?
No, way too many variables. However, your valvetrain will be more stable if corrected.
Theres got to be a reason why when Jesels are installed the installed valve stem height is relative to where the subplates mount on the head.
