Jetta Engine Codes

I am trying to replace the muffler system on my 88 Jetta, but apparently I need to know the engine code to do this. I cant find it on the engine block itself, and after pouring through information online, I still cant figure out what the code could be. Any idea how I could find out what it is? Maybe some specs would help. 88 Jetta, 1.8 litre 4 cylinder, 4 door, standard. Thanks for all the help

There are a few engines you could have, three 8-valves or a 16-valve. The number is found on the flattened pad of the engine block right whee it meets the cylinder head. It is on the car's front side just below the flange where the upper radiator hose joins the cylinder head.