SDK_CONTAINER_IMAGE

diff --git a/.github/workflows/beam_PostCommit_Python_Arm.yml b/.github/workflows/beam_PostCommit_Python_Arm.yml
index acefdcc..aa946dd 100644
--- a/.github/workflows/beam_PostCommit_Python_Arm.yml
+++ b/.github/workflows/beam_PostCommit_Python_Arm.yml

@@ -56,7 +56,7 @@
     runs-on: [self-hosted, ubuntu-24.04, main]
     # Python ARM PostCommit uses prebuilt Snapshots SDK images, so it no longer
     # spends hours on multiarch container builds. Keep headroom for the IT suite.
-    timeout-minutes: 180
+    timeout-minutes: 360
     strategy:
       fail-fast: false
       matrix:
@@ -105,12 +105,9 @@
         with:
           gradle-command: :sdks:python:test-suites:dataflow:py${{steps.set_py_ver_clean.outputs.py_ver_clean}}:postCommitArmIT
           arguments: |
-            -PuseWheelDistribution \
             -PpythonVersion=${{ matrix.python_version }} \
             -PusePrebuiltSdkContainer \
         env:
-          # Use multiarch images published by Publish Beam SDK Snapshots.
-          SDK_CONTAINER_IMAGE: gcr.io/apache-beam-testing/beam-sdk/beam_python${{ matrix.python_version }}_sdk:latest
           USER: github-actions
       - name: Archive Python Test Results
         uses: actions/upload-artifact@v7

diff --git a/sdks/python/test-suites/dataflow/common.gradle b/sdks/python/test-suites/dataflow/common.gradle
index abe7867..e998ffe 100644
--- a/sdks/python/test-suites/dataflow/common.gradle
+++ b/sdks/python/test-suites/dataflow/common.gradle

@@ -145,20 +145,22 @@
 
 task postCommitArmIT {
   def pyversion = "${project.ext.pythonVersion.replace('.', '')}"
-  dependsOn 'initializeForDataflowJob'
   // When -PusePrebuiltSdkContainer is set, skip building/pushing a multiarch
-  // SDK image and use SDK_CONTAINER_IMAGE from the environment instead (e.g.
-  // gcr.io/apache-beam-testing/beam-sdk/beam_python3.x_sdk:latest from Snapshots).
+  // SDK image and use SDK_CONTAINER_IMAGE from the environment instead.
   def usePrebuiltSdkContainer = project.rootProject.hasProperty(['usePrebuiltSdkContainer'])
-  if (!usePrebuiltSdkContainer) {
+  if (usePrebuiltSdkContainer) {
+    dependsOn 'installGcpTest'
+  } else {
+    dependsOn 'initializeForDataflowJob'
     dependsOn ":sdks:python:container:py${pyversion}:docker"
   }
 
   doLast {
     def testOpts = basicPytestOpts + ["--numprocesses=8", "--dist=loadfile"]
+    def sdkLocation = usePrebuiltSdkContainer ? 'container' : project.ext.sdkLocation
     def argMap = [
         "test_opts": testOpts,
-        "sdk_location": project.ext.sdkLocation,
+        "sdk_location": sdkLocation,
         "suite": "postCommitIT-df${pythonVersionSuffix}",
         "collect": "it_postcommit",
         "py_version": project.ext.pythonVersion,
@@ -167,6 +169,10 @@
     def cmdArgs = mapToArgString(argMap)
     exec {
       executable 'sh'
+      if (usePrebuiltSdkContainer) {
+        environment 'SDK_CONTAINER_IMAGE',
+          "gcr.io/apache-beam-testing/beam-sdk/beam_python${project.ext.pythonVersion}_sdk:${project.sdk_version}"
+      }
       args '-c', ". ${envdir}/bin/activate && ${runScriptsDir}/run_integration_test.sh $cmdArgs"
     }
   }