You've been on here a while, you should know what happens if you don't have the block machined properly... At least I hope you've seen the term "500 mile rebuild" on here. Repeatedly.

If you've got a damn good machine shop that knows 3800s, more power to ya, but as you probably already know it's much cheaper and less work to find a junkyard short block, rather than try and have a machine shop line-hone all of the mains and everything else, deck and surface everything, etc...