Push rod length

Solid lifter pushrods tend to be about .25" - .30" longer than hydraulic applications because the lifter "cup" is lower in the lifter body. Kind of like a bottomed-out hydraulic lifter. i.e.: 273 small block solid adjustables = 7.500" ball/cup vs 340 Six Pak hydraulic adjustables =(approx.) 7.21"-7.23" ball/cup. But there can be differences between lifter manufacturers. Best not to take anything for granted.