What's needed to change to roller?

I have a 454 with a 268 hyd cam in my 4x4 Blazer but it's coming out and going into my 80 Malibu. I'm adding a set of aluminum heads along with a roller cam. Never ran one before and need to know if there is anything different I need for them. I'm putting on a set Comp Pro magnums, new pushrods and the rollers lifters to match the cam. Is there anything that needs to be done to the block, distributor, tining chain, cover or anything else??

Thanks