This is my first post and how do I post pictures?

I found for 700 bucks 2003 Chevy Express 3500 12 passenger van with a 6.0L / 4L80e (I think) drives really strong with a half million miles (455000) yeah a half a MILLION, everything I need for a rebuild swap but not sure if I want to use it for my swap because it drives pretty decent. It was posted on Craigslist 3 hours before I bought it. LOL. what a blessing

I searched the net on the best way to dig it out of the van and most have took the front end off and pulled it out the front.

A couple a buddies of mines say to completely replace everything due to the high miles and just check and use the block and start from there, any suggestion how to approach this motor rebuild. I want to be close to 500 hp when I'm done.

Its going in a 71 Camaro my future project. Not a race car but I want to be able to drive around and scare the crap out of some kid in his new Mustang.

I plan on parting it out to recoup some or most of my initial cost, 500 HP is the goal but I was wondering should I replace the rotating assembly due to the high miles or just have everything checked and if good, grind, polish and balance whats good, replace whats worn out with upgrades and put it back together. It shouldn't take much to get 500 HP with a cam and LS6 intake and a few other parts. I want to use as much as I can if possible. Its that half a million miles that's got me concerned. LOL