What you are talking about is a M4A1E4 with the E9 suspension. It's just a M4A1 with a 76MM gun, hence the E4 designator and it has the E9 spaced out suspension as noted by others. No change to the engine deck since all the mods had to do with the main gun and running gear. Not all Pakistani M4A1E4s had the E9 suspension. Some just had the normal VVS.
M4A1E4s with E9 suspension:
M4A1E4s with normal VVS: