As I understand it you also need to change the cam to a solid lifter type. The lift profiles are different.
Still, to the original question, I'd like to know too if there is any reason you can't run solids in a block originally equiupped with hydraulics, i.e. are they the same diameter, to you need different pushrods? I've heard that unless you can find a set of NOS lifters that your better off with solids.
