i was thinking about converting my 350 to a roller cam but i was going to use a stock spider tray what do i need to do to install it. is it just a matter of drilling and tapping the block

 

Your project will be a lot simpler if you used roller lifters especially made for non roller blocks.

 

It can be done but but I agree with z28pete, do the retro kits. That is what I am doing, retro lifters, cam, and timing set, etc.It is considerabley more expensive that's for sure. I will have nearly 1200.00 in my valve train when done.