ferrydude:
You are right! As I pointed out earlier, there is no fuel saving on the DC-8, both 50 and 60 series (don't know about the 70 series, haven't flown them much) with shutting down an engine in cruise. Even at low weights you will not save any fuel doing this, and believe me, I have done quite a few 3 engine ferries on them.
Proper 3 engine ferry technique for DC-8 is as follows (outboard engine inop): Calculate MTOW for the particular runway. Use V speeds for the MTOW (high speeds). Spool inboards to 1.4 Epr, brakes on. Set T/O thrust on inboards, when T/O EPR is reached, release brakes. At 80 KIAS bring in slowly the outboard engine (best done by the F/E). With the gradual power from the outboard coming in, compensate with rudder. Outboard engine has to be at T/O EPR before 110 KIAS.
Since using V-speeds for MTOW, it doesn't matter if you would loose another donk at V1, since you're actually allready at Vr for your actual weight....
Hope this clears things up a bit.
Ou dronkie, kom man ons drink nou 'n dop!!!!