diff --git a/autotest/t503_test.py b/autotest/t503_test.py
index 797e2eea1..d7a30a7cb 100644
--- a/autotest/t503_test.py
+++ b/autotest/t503_test.py
@@ -4,20 +4,20 @@
 import pymake
 
 
-def download_mf6_distribution():
+def download_mf6_examples():
     """
-    Download mf6 distribution and return location of folder
+    Download mf6 examples and return location of folder
 
     """
 
     # set url
-    dirname = 'mf6.1.0'
-    url = 'https://water.usgs.gov/water-resources/software/' + \
-          'MODFLOW-6/{0}.zip'.format(dirname)
+    dirname = "mf6examples"
+    url = "https://github.com/MODFLOW-USGS/modflow6-examples/releases/" + \
+          "download/current/modflow6-examples.zip"
 
     # create folder for mf6 distribution download
     cpth = os.getcwd()
-    dstpth = os.path.join('temp', 'mf6dist')
+    dstpth = os.path.join('temp', dirname)
     print('create...{}'.format(dstpth))
     if not os.path.exists(dstpth):
         os.makedirs(dstpth)
@@ -30,26 +30,53 @@ def download_mf6_distribution():
     os.chdir(cpth)
 
     # return the absolute path to the distribution
-    mf6path = os.path.abspath(os.path.join(dstpth, dirname))
+    mf6path = os.path.abspath(dstpth)
 
     return mf6path
 
 
-out_dir = os.path.join('temp', 't503')
+out_dir = os.path.join("temp", "t503")
 if os.path.exists(out_dir):
     shutil.rmtree(out_dir)
 os.mkdir(out_dir)
 
-mf6path = download_mf6_distribution()
-distpth = os.path.join(mf6path, 'examples')
-folders = sorted([f for f in os.listdir(distpth)
-                  if os.path.isdir(os.path.join(distpth, f))])
-
-for f in folders:
-    src = os.path.join(distpth, f)
-    dst = os.path.join(out_dir, f)
-    print('copying {}'.format(f))
+mf6path = download_mf6_examples()
+distpth = os.path.join(mf6path)
+# folders = sorted([f for f in os.listdir(distpth)
+#                   if os.path.isdir(os.path.join(distpth, f))])
+
+exclude_models = ("gwt",)
+exclude_examples = ("sagehen", "keating",)
+src_folders = []
+
+for dirName, subdirList, fileList in os.walk(mf6path):
+    dirBase = os.path.basename(os.path.normpath(dirName))
+    useModel = True
+    for exclude in exclude_models:
+        if exclude in dirBase:
+            useModel = False
+            break
+    if useModel:
+        for exclude in exclude_examples:
+            if exclude in dirBase:
+                useModel = False
+                break
+    if useModel:
+        for file_name in fileList:
+            if file_name.lower() == "mfsim.nam":
+                print('Found directory: {}'.format(dirName))
+                src_folders.append(dirName)
+src_folders = sorted(src_folders)
+
+folders = []
+for src in src_folders:
+    dirBase = src.partition("{0}mf6examples{0}".format(os.path.sep))[2]
+    dst = os.path.join(out_dir, dirBase)
+
+    print('copying {} -> {}'.format(src, dst))
+    folders.append(dst)
     shutil.copytree(src, dst)
+folders = sorted(folders)
 
 exe_name = 'mf6'
 v = flopy.which(exe_name)
@@ -58,14 +85,14 @@ def download_mf6_distribution():
     run = False
 
 
-def runmodel(f):
+def runmodel(folder):
+    f = os.path.basename(os.path.normpath(folder))
     print('\n\n')
     print('**** RUNNING TEST: {} ****'.format(f))
     print('\n')
 
     # load the model into a flopy simulation
-    folder = os.path.join(out_dir, f)
-    print('loading {}'.format(folder))
+    print('loading {}'.format(f))
     sim = flopy.mf6.MFSimulation.load(f, 'mf6', exe_name, folder)
     assert isinstance(sim, flopy.mf6.MFSimulation)
 
diff --git a/flopy/mf6/data/dfn/gwt-dsp.dfn b/flopy/mf6/data/dfn/gwt-dsp.dfn
index 62df43101..ea56e8c0f 100644
--- a/flopy/mf6/data/dfn/gwt-dsp.dfn
+++ b/flopy/mf6/data/dfn/gwt-dsp.dfn
@@ -7,7 +7,7 @@ shape
 reader urword
 optional true
 longname deactivate xt3d
-description deactivate the xt3d method to and use the faster and less accurate approximation.  This option may provide a fast and accurate solution under some circumstances, such as when flow aligns with the model grid, there is no mechanical dispersion, or when the longitudinal and transverse dispersivities are equal.  This option may also be used to assess the computational demand of the XT3D approach by noting the run time differences with and without this option on.
+description deactivate the xt3d method and use the faster and less accurate approximation.  This option may provide a fast and accurate solution under some circumstances, such as when flow aligns with the model grid, there is no mechanical dispersion, or when the longitudinal and transverse dispersivities are equal.  This option may also be used to assess the computational demand of the XT3D approach by noting the run time differences with and without this option on.
 
 block options
 name xt3d_rhs
diff --git a/flopy/mf6/modflow/mfgwtdsp.py b/flopy/mf6/modflow/mfgwtdsp.py
index d5a119d53..493fff411 100644
--- a/flopy/mf6/modflow/mfgwtdsp.py
+++ b/flopy/mf6/modflow/mfgwtdsp.py
@@ -17,8 +17,8 @@ class ModflowGwtdsp(mfpackage.MFPackage):
         Do not set this parameter. It is intended for debugging and internal
         processing purposes only.
     xt3d_off : boolean
-        * xt3d_off (boolean) deactivate the xt3d method to and use the faster
-          and less accurate approximation. This option may provide a fast and
+        * xt3d_off (boolean) deactivate the xt3d method and use the faster and
+          less accurate approximation. This option may provide a fast and
           accurate solution under some circumstances, such as when flow aligns
           with the model grid, there is no mechanical dispersion, or when the
           longitudinal and transverse dispersivities are equal. This option may