no it doesn't make it any stronger, but stroking will definitely help make more power. the stock block is good to around 500-550hp but a few guys here and there make that and more, but they will be the first to tell you that it is pushing the limits. you can also get a girdle which some say helps to make it stronger but others will only say help to keep the parts in place when the block actually splits. it is all in the build. you can easily see 500 to the wheels on a well built stock block. don't be discouraged, 450-500hp is a fun ass motor. honestly, I won't go much further than 500-510 but I don't drive it everyday and I won't be spraying it too much either.
If you have the cash for an "R" or A4 block, then by all means get it. If not then there is always the sportsman block but many who have that will say that they should have spent a few hundred more and gotten one of the others. sometimes you can find one used or still new in the crate for sale from someone who didn't use it for a pretty good price.
if that isn't an option, then run what you got and just take every precaution you can. thats about all you can do.