Hi Rob,

Name is Perry.

You definitely cannot use a cast iron camshaft with roller lifters - even with the lobe reprofiled.
The cast cam is not hard enough for use with roller lifters. The roller cam profiles are special steel cores which are also hardened. I have attached a picture of my 1.9 HO roller cam. It is machined from a steel blank. The factory for roller cams had special hardened lobes pressed onto a shaft - it was cheaper to manufacture than machining a steel cam.
Mine is an aftermarket cam for the 1.9 HO.