[Retro]

They are good when they're good Clarke, I had a 6v92 turbo in an 83 wanderlodge and it was fine other than I had to wind it up in the hills and hard on fuel. But if there no good some might want to opt for a newer 4 stroke, they are more efficient, cheaper to rebuild and easier to get parts for. I have yet to see anyone pulling a 60 series or any other 4 stroke for that matter and installing a 2 stroke.
It just wouldn't make sense.
My 8.3 is also full mechanical with the p7100 injector pump, very common and very reliable. I never have to add oil and average 10mpg with power to spare. And love the sound!! Kinda like a jet engine, awsome!! The allison world 6spd is nice too. Smooth!!