Having been down this road last summer, I'll give my thoughts. The truck started cold and ran flawlessly but would not start well when hot at all.
First off, I tried messing with the timing, both ways, to no avail. Even tried skipping a tooth on the IP gear itself. Eventually, I bought a Mini Moose injection pump from Mel for around $700. For the record, when I called and talked to him he said that most of the time with these pumps its not the head/rotor but rather the calibration of the many fuel adjustments these pumps have. Either way, I put the Moose pump on and the truck really ran great. However it still took, in my opinion, excessive turning to crank when warm.
So after much frustration, I bought a brand new Nippo-Denso style starter and replaced ALL battery cables (grounds too) with 2/0 cable with properly crimped ends. Truck began starting very fast cold and warm. It was a noticeable difference.
I say all that to say this. If you think there is a chance your starting speed has began to diminish over time, replace the starter/cables/batteries and see what happens. It's hard to say if that would have fixed my problem originally or if it would have bought me more time. I don't know. Either way, I now have a high-end pump, great starter and a quick-starting truck.