I have an 86' coupe and was able to read the engine number with a strong flashlight and getting just the right viewing angle, I have a pipe in the way also, but if you keep moving the flashlight and your head around you can see it. Oh yeah, it helps if you can get down there and clean the area first.
What do you want to check? If it's the original engine?
you can look at the cyl head surface in front of the pass. side cyl. head. It will have a suffix code wich has to correspond to the suffixes for that year and the number below it hsa to match the last portion of the VIN. If that's the case you'll know what engine you have!
And for heads, if they're original non alu heads they're the
462624 76cc smog heads (thin castings!) w/ 1,94 & 1,5 valves. Pressed in studs.