The 7.3 and 7.4 versions are very similar. The CLSA program is currently a combined 7.3-7.4 program. For the LSA application build, we prefer you use v7.3 of Pega to complete the app build exam since our graders use 7.3 to grade the exam. Using v.7.4 could lead to problems during grading. The 7.3 image is supplied in the Lead System Architect (7.3-7.4) course at https://academy.pega.com/library/73-74/lead-system-architect.