Mechanical Rocker Arm Ratios...

Since I've been gathering a few items to stuff in the 4-4-0 for the Dart,I have amassed a few x-tra things along the way so I could have a few choices for the final decision in the end combo which leads to one of my questions of many but I will address this one 1st...mechanical adjustable rockers actual ratios...I am sure there is a way for an average guy to figure the true ratio for himself so let er rip on the hows and not hows of accomplishing it...as a question was raised about Cranes versus Isky,Mopar and others being iron or alum or stainless steel,I myself have a 2 sets of iron Iskys 1.5's and a set of Kmj Perf stainless steel rollers 1.6's with the ball and ball style pushrod....so what are your thoughts and any tech material supporting the pros and cons of diff brands and their actual ratios versus stock or aftermarket rollers, mechanical adjustables,and which brand you deem good or bad,which you find more reliable whether it be the adjusters and nut to the roller part of it or type of bushings/needle bearings or whatever I want to hear about your experiences and thoughts and actual usage,guess we need to include the shafts pros and cons along with the hardware....thanks and keep it MOPAR