I found 8v71 used whats the $$$$ value

[Lonnie time to go]

Have a friend of a friend who has several 8v71 engines
some of these engines are in semi trucks and some are joined
together for something else
I am considering getting one know for future use. maybe to rebuild at a later date.
please give me opinions as to the value of engine if it runs  or dont.
thanks

[Dallas]

If you have a GMC a normal truck engine isn't gonna work in your bus...
GMC Bus engines are Left Hand Turn.

[NJT5047]

Even if they were LH engines, unless they were verifiably recent rebuilds and proven good running engines, they don't have much value at all.   
The bolted together units may be V12s...Detroit bolted all sorts of combos together for various applications.   
If they've been sitting with the air intake uncovered for long, they are worth whatever scrap value would bring...minus shipping and handling. 
Unless you are qualified to self-rebuild, they are almost too expensive to overhaul. 
An 8V71 delivered to most quality repair facilities may cost between $8K to $15K to completely rebuild.....
A good running takeout would be worth $2K to $3K...typically.   
Have you considered looking for a LH 6V92 out of a GM?  You'd definitely want a takeout with all the accessories.   Give you a right good bit more HP. 
Maybe the 8V71  could be turbocharged?  It could be turbocharged, just not sure about the GM application....and transmission's ability to handle the increased HP. 
Dallas? 
JR

[Dallas]

Yup,

Gotta agree with JR on this one,

If you are going to go to the trouble to have a spare, you might as well go with the 6V92, even though I'm personally not fond of the wet sleeve engines.

There's probably not much difference in overhaul costs and you can see about an 80 HP power increase.

One problem with going to the 92 series will be cooling, but that can be gotten around by making sure your cooling system and all assorted peripherals are up to snuff.

Switching a RH engine to become a LH engine isn't that difficult, but really isn't for the faint of heart. If you have the engine torn down far enough to do that, you might as well have the heads done, the deck surfaced, new bearings, check the liners and pistons and replace as needed. In short, you will have done a minor overhaul when you are finished.

Good Luck!

Dallas

[Barn Owl]

I have a 8V71 in my bus; but, having driven a bus with a 6V92 upgrade, I agree that it is the way to go. There are many transits out there just waiting to be a donor. The nice thing about LH is that the supply is far greater than the demand, so you should find a lot a bang for the buck on that upgrade.