A little engine help please.

I have a friend that just bought a 90 civic hatch and we have no clue what engine is in it, the guy he bought it off of said it came out of an integra and is a 1.6L however he had someone else that knew a little about hondas look at the engine and said it's a 1.5L.
I have never worked on any hondas and this is only the second one I've been in so if someone could maybe help me out on this because there's several things that needs to be fixed on this car.

Here are some of the engine codes I found on the side of the head; PM0-3; A341L0185, and this is off of the side of the trans; L3-1353275.
The only thing I know about it is that it's a single cam 16 valve engine, so any help would be apreciated.

WHen you open your hood.. Look on the engine block.. usually right under the head somewhere you will see what it is.. Its stamped right in the block... Its usually on the side your dizzy is..

It's a plate like this: http://img.photobucket.com/albums/v473/CivicSpoon/plate.jpg
The bigger letters and numbers is what you're looking at, like on this one is an H22A.

Thanks I'll look for the ID bar tomorow.

It's a plate like this: http://img.photobucket.com/albums/v473/CivicSpoon/plate.jpg
The bigger letters and numbers is what you're looking at, like on this one is an H22A.
to add to that...
http://www.4thgenerationcivic.com/Photos/members%20rides/members%20pics/dano_026.jpg

the little plate was painted blue on this block.... it's easy to spot the location you'll be looking for on your block