Since your 8V-71 is already a turbo engine, for me it is a no brainer to overhaul your engine and reinstall it. Then later you can turbo it. Yes it is a tight fit, but will ultimately be the cheapest way to go.
Don has confirmed that since the pistons and liners are different - it doesn't make sense to overhaul it here as an 8V71N and then later turbo it - the work should all be done at once.
I can tell you from experience that turboing an 8V-71 (I also have an air to air intercooler) REALLY wakes them up and makes driving a total joy. Driving from L.A. to Las Vegas-when pulling my car, went from having to down shift on several up grades to not down shifting except for Cajon Pass and Baker hill-both of which I pull 15mph faster. The 71 series is a more forgiving engine-it is more tolerant to overheating, overspeeding and with the dry cylinder liners, don't have to worry about coolant in the oil if the liner seals start to leak-like on the 92 series.
Great thoughts Tom. We are open to either an 8V71T or 6V92TA, and a lot will come down to what Don ultimately recommends.
BTW - unlike some bus nuts, we aren't primarily looking for a "hot rod" driving experience. Cruising at 55mph in the slow lane is plenty fine for us.
Here are our ultimate goals in our engine overhaul:
1) Reliable & Rock Solid. The bus is our home, and we want to trust it to get us where we are going with minimal fuss. We aren't going to demand tons of miles from her - roughly 10k year, but in use in potentially all four seasons of climate and in all corners of the country.
2) Suitable for travel at higher elevations, and on steep backroads and camp roads.
3) As fuel efficient as possible. (This is more important than speed...)
4) Good hill climbing abilities - even on hot days. We don't mind being passed, but do not want to end up a traffic obstacle stuck at 15mph.
5) Great hill descending capabilities without riding the brakes. Jakes are a must.
6) Top speed is not a concern - we cruise at 55-65mph or else the girl eeps too much.
7) We don't need to do everything on the cheap, but we don't have anything close to a blank check either.
Acceleration for merging is nice to have, but we are rarely into passing. We don't need a "hot rod" - especially if it comes with a hot engine.
9) Geek points are nice if a DDEC gives us things like cruise control, more instrumentation, and especially more engine safety systems. But we have plenty of geek points already so we can give these up if it costs too much.
10) Reliable and rock solid. Again the most important goal.