6.0 LS Question

[g-machine]

I am going to look at a 6.0 LS engine out of a Silverado work truck. It has 215000 miles, does not burn or leak oil, with no strange noises (what I am told). It was in a truck up until last week. No wiring harness. Asking price is $650 o.b.o. - is this a good deal? What would be a good offer and what should I watch for? I would plan on a full rebuild due to how many miles plus I would like to make upgrades for performance. This would eventually go into my 79 Camaro.

Any help would be appreciated.

Thanks,
George