Seriously, hit up CL &/or your local Junk Yards for a lower mileage L67 3800... vin code 1 not K. I picked up a lower mileage engine out of a bonnie and tore it apart and gave it a good "once over" and new gaskets and she's running great for less than $1000. Its alot easier to get a complete engine, and truthfully if you get one and just clean it up and replace the gaskets you should be just fine. Most stock lower ends are good for well over 300whp so pick one up, check it out, replace what you NEED to, and drop it in and tune.
If you go to a Junk Yard tho, most of them don't know the difference (at least around my parts) so make sure it is a Series II not a Series 1 with a M67 like I had 1 place try to sell me lol. Or a GenV/L32 if you really want to jump into the power with a Series III.