a518 shifts slow

I have a 91 w250 with a cummins in it and a a518 auto. The tranny has been totally redone with kevlar clutches and upgraded steels. The kickdown cable has been set to max out the line pressure under full throttle. The guy who built the tranny said everything else in the tranny checked out good when he built it. The tranny shifts real firm and quick it just takes too long to do it. I understand that with increased line pressure the tranny holds gears a little longer but when I get into it it will sit at the redline for a few seconds before shifting I have to back off on it so it will shift a little quicker but it still seems slow. Any help appreciated. I was thinking the solenoid pack was maybe just worn out or should the tranny guy have been able to tell that by looking at it.

if it's adjusted to the max, you might have a bad valve in the valve body. Go back to the guy who rebuilt your transmission and have him check out the throttle valve, make sure it's not binding in its bore.

That was how it was set. It's not because of bad valves.