Do not forget that the LDS-1A uses the ONE-HOLE injectors with the Code B pump. The LDS-1 uses the TWO-HOLE injector, which was a change and not done initially. The TM (226-34) is very specific that the -1 must have two-hole injectors installed. The pumps (Code B and Code F) are interchangeable but have to the specifically identified as calibrated for B engines (-1A) or F engines (-1).
So...is it just fuel delivery and timing?
More timing reduces EGT, and puts the heat in the piston and block, it also reduces smoke, but makes for a rough idle. I believe that Gimp made the comment early in this thread that there is a distinct difference in the sound of an LDS465 and a LDT465. I agree, it is dramatic.
Has anyone that has turned up the fuel added any timing? Say 5 degrees more advance?