Another lifter question

Which short block arre you looking at? The LA based ones will have a std flat tappet cam installed. You cannot run roller lifters of any type on a flat tappet design cam. If it's a Magnum based short, I believe they will have the hydraulic roller type cam installed, but doesnt come with the spider in the valley area and retainers for the lifters. All retro roller packages are hydraulic designs. They are meant to replace a std hyd cam. Solid rollers make big power, but require a little more attention to run,and cam choice for a street driven car needs to be done carefully. Lash normally will need to be checked and re-set about every 5K miles. I do them in the spring, and again if they get noisey or performance changes.