Yes, leave the shortblock alone. Just re-gasket everything like Scotty mentioned and go with that. If you take anything loose in the block you will need machine work guaranteed. There are guys running 3-400+ WHP on stock blocks so it's a non-issue.

Also, be sure to put a little thread sealer on the rear cover bolts as they like to loosen up and leak over time. Some have found they are finger tight when they check the factory ones.