Nothing wrong with a good low mileage L67 or L36 block. They are the same thing when it comes to bottom end of things.

My suggestion though would be.......if it ain't broke don't fix it! LOL. Do the recommended maintenance of course. At your mileage I would change out the timing chain and dampener before doing any serious modding. A stock replacement should be just fine unless you're going to go cam while inside.