I'm looking at doing the same thing... Will there be enough oil pressure to operate the lifters? Will the head not flood with oil since there is the extra drain missing?
For me the only reason I ask is I have a good hydro head and a good mechanical block... I just wonder what is involved, not worried about performance. I've had several mechanical headed motors and hydro ones too and for the average tune I highly doubt there is a big advantage from one over the other. I could never notice any. If there is a difference than I'd like to see the numbers to prove it... now a solid roller lifter....that would be a different story!.... someone needs to make some!