Blueprinting... Educate the uneducated
All this hype on cast/forged rockers having ratios all over the place seems very suspicious...take a factory or an aluminum rocker that has been determined to be "out of spec" for ratio and change the adjuster length, it will change the ratio! as modern (even 60's) manufacturing process' would not send out a product as simple as a rocker (2 precision processes: shaft bore and adjuster thread boss and potentially the tip face height but not really as even that is highly controlled) that varies much as the jigs used to drill these are rigid. With everyone knowing the decks of these blocks are not square, that changes the relationship between the rocker shaft and the camshaft axis. Even the truest rockers (T&D, HS, etc) are going to show a slight variation in rocker ratio if measures on the non squared up block. I guess the only way test this would be to get some 'out of spec' rockers and accurately measure the distance from the center of the shaft bore to the tip of the adjuster, equalize this across a few and then test them against each other. Post your results if they are still wonky. Should have been a covid incubation project for me.....
"...A unique feature with the shaft mounted rocker arms such as those found on the ...(Mopar LA)... engines is that the solid lifter or lash adjusting versions can be measurably variable in the rocker arm ratio depending upon where the lash adjusting screw is positioned within its range of travel. Where changing the pushrod length on the stud mounted or trunion type of rocker arm affects the geometry of the rocker and not the rocker arm ratio, changing the pushrod length on the shaft mounted (LA) rocker allows for some deviation from the advertised amount of rocker arm ratio. .... What makes this possible is that the contact point for the pushrod at the bottom of the adjustment screw changes in relationship to the center of the pivot point (shaft) as the adjusting screw is moved up or down. (see illustration)..."
All this hype on cast/forged rockers having ratios all over the place seems very suspicious...take a factory or an aluminum rocker that has been determined to be "out of spec" for ratio and change the adjuster length, it will change the ratio! as modern (even 60's) manufacturing process' would not send out a product as simple as a rocker (2 precision processes: shaft bore and adjuster thread boss and potentially the tip face height but not really as even that is highly controlled) that varies much as the jigs used to drill these are rigid. With everyone knowing the decks of these blocks are not square, that changes the relationship between the rocker shaft and the camshaft axis. Even the truest rockers (T&D, HS, etc) are going to show a slight variation in rocker ratio if measures on the non squared up block. I guess the only way test this would be to get some 'out of spec' rockers and accurately measure the distance from the center of the shaft bore to the tip of the adjuster, equalize this across a few and then test them against each other. Post your results if they are still wonky. Should have been a covid incubation project for me.....
"...A unique feature with the shaft mounted rocker arms such as those found on the ...(Mopar LA)... engines is that the solid lifter or lash adjusting versions can be measurably variable in the rocker arm ratio depending upon where the lash adjusting screw is positioned within its range of travel. Where changing the pushrod length on the stud mounted or trunion type of rocker arm affects the geometry of the rocker and not the rocker arm ratio, changing the pushrod length on the shaft mounted (LA) rocker allows for some deviation from the advertised amount of rocker arm ratio. .... What makes this possible is that the contact point for the pushrod at the bottom of the adjustment screw changes in relationship to the center of the pivot point (shaft) as the adjusting screw is moved up or down. (see illustration)..."