I agree you should use the 180 method since you are new to adjusting the valves.As far as the cams I prefer the Lunati.You will have a huge difference in mid range torque with the Lunati.Top end H.P. will be close between the two cams.As far as the .557 it is the only MP cam I would use if I had no other choice.Ultradyne,Engle and others have some terrific solid lifter cams.One note if you decide to run a solid invest in a set of edm (oiling) solid lifters.