I removed my rack limiter on my 617 and it made a huge difference. All pumps are gunna be a little different so your results might not be exactly the same as mine. I'd say go for it though. I also messed with my torque capsule. I wouldn't recommend this unless you have a back up pump in stock form to replace if something goes wrong. I adjusted mine to the point where it belched black smoke at idle. When I tried to reverse my doings, it made it not want to idle smoothly. It kept loping. I put in a stock pump I had for a spare, removed the alda, removed the rack limiter, and timed it to 28* with the drip method and haven't looked back since. She can belch black smoke right now right before it builds 18psi worth of boost and chirp the tires at each shift.

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1981 300 SD 213k miles "Stock for now"
1999 Super Duty 7.3L 113k miles
1981 300 SD 180k miles "Heavily modified" SOLD