Driving the E-6 350

[Licensed to kill]

Just covering as many bases as I can think of, ran the numbers on the gear ratios in the triplex that I intend to put behind the E-6 350 (2Valve) and the RPM drop is pretty constant +-250 between gears. From what I have gathered on the power range of the econodyne 350, thinking that shifting @ around 1700, dropping to 1450 should keep this motor in it's "sweet spot" where it should pull well, not lug, and get as good economy as possible, unless my info is incorrect. Perhaps even 100-200RPM lower if bobtailing. I understand that the triplex is not really made for the kind of power the 350 puts out but don't intend to pull anything heavy, at the MOST maybe 20,000 pounds but more likely much less. The plan is to only pull a holiday trailer. Any thoughts/advice is much appreciated whether it is "sounds like a good plan" or "yeah, that's not going to work well because......." or "OK but be careful about......" or "make sure to check...............first". Truck is a LOT of work and $ and I want to have as much info as possible to make sure I don't get something all wrong. BTW, the clutch from the triplex looks pretty good, single disk push to release. Not sure yet if the pressure plate bolts up to the flywheel on the E-6.