I would basically agree with what Monte is saying, unless there is a desired/targeted hp level you're after, that could easily be reached with the lesser cost/easier option.
If you're trying to make the most power you can, then buy the highest power potential heads you can afford.
For a super class 499, if I had CNC ported MW size SR's, I'd just keep using them until I was looking to make a big move in power........ at which point you'll have to start thinking about a real block.
This is my thinking as well. I like the 440-1 CNC345 over the SR CNC, but unless you need the incremental increase, save your money for the big change which includes an aftermarket block, etc. The head swap you asked about is not worth the cost, IMO.
Now your last post said your SR's need to be replaced. I would go with 440-1 CNC345 and better rockers until you make the big leap.
