Hi Rick,
Thanks! Here is the command I used:

3dZcutup -keep 29 101 -prefix topup2.5GRAPPA_iout_alzc.nii topup2.5GRAPPA_iout_al+orig.
++ 3dZcutup: AFNI version=AFNI_16.1.25 (Jun 15 2016) [64-bit]
*** -keep 29 101 goes past last slice 69

The 3dinfo output of the dataset is below:

3dinfo topup2.5GRAPPA_iout_al+orig.
++ 3dinfo: AFNI version=AFNI_16.1.25 (Jun 15 2016) [64-bit]

Dataset File: topup2.5GRAPPA_iout_al+orig
Identifier Code: XYZ_aM1OgtPY9K9_dyDMcrjzAg Creation Date: Mon Jun 27 14:35:21 2016
Template Space: ORIG
Dataset Type: Anat Bucket (-abuc)
Byte Order: LSB_FIRST [this CPU native = LSB_FIRST]
Storage Mode: BRIK
Storage Space: 17,478,720 (17 million [mega]) bytes
Geometry String: "MATRIX(0,0,2.5,-86.25,2.5,0,0,-149.7524,0,-2.5,0,113.303):102,102,70"
Data Axes Tilt: Plumb
Data Axes Orientation:
first (x) = Anterior-to-Posterior
second (y) = Superior-to-Inferior
third (z) = Right-to-Left [-orient ASR]
R-to-L extent: -86.250 [R] -to- 86.250 [L] -step- 2.500 mm [ 70 voxels]
A-to-P extent: -149.752 [A] -to- 102.748 [P] -step- 2.500 mm [102 voxels]
I-to-S extent: -139.197 -to- 113.303 [S] -step- 2.500 mm [102 voxels]
Number of time steps = 6 Time step = 8.00000s Origin = 0.00000s
-- At sub-brick #0 '#0' datum type is float: -198.612 to 3700.47
-- At sub-brick #1 '#1' datum type is float: -198.242 to 3764.38
-- At sub-brick #2 '#2' datum type is float: -210.951 to 3730.53