4L80e. Lowered the MPH vs APP under 50% throttle. With the manual pump conversion a lot of the APP levers are modded by welding parts of a manual throttle pedal to the APP lever. The problem I had and what I've read in many places is the manual pump doesn't accelerate as fast under 50% throttle as the electric pump. The the low throttle angle and lack of continued acceleration cause the shifts to stall or hang until you either lift the throttle or increase mph.
One of the big conversion write ups requires the use of piggy backing a separate TCM to correct this. The author even states he tried to burn chips to achieve proper shifting but never had any luck. I've burnt two chips just for the shift table and I'm happy with it. I suppose the only caveat would be the difference in the geometry of the modded APP levers, but mine is working great.
This was my parents truck and they've been living with it this way for years. Thank you again for the XDF, huge leap forward for the truck as far as driveability!
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