Jac Mac? Are you thinking the original side oiler solid lifter blocks don't get enough
oil all ready? With the later blocks that do allow hydraulic lifters you have to use a restrictor to keep from getting TO MUCH
oil on the lifters.
From an engine rebuilder\suppliers view point I can see why they would recommend hydraulic lifters, every time. Why would a builder want to go through the extra hassle of breaking in a solid lifter cam? Easier to just sell hydraulic and be done with it. And what if the customer does not follow precisely the solid lifter breakin requirements? As a builder YOU still 'look bad' even if it wasn't your fault.