I was looking at the old brochures on usmb and noticed that in every ad with a GL there is also a DL. They look exactly the same on the outside. Are there any differences or is one just a cheaper model?

DL is the cheaper model. AFAIK, there are no 4WD DL cars, no turbos or air rides either....

And many times the DL had black bumpers while the GL has body-colored ones, stuff like that...

Actually....

The DL was available in 2WD and 4WD

The DL was the base model pretty much, it just had simple guages speedo, fuel and temp, thats it. only had single range 4WD, no power features, black bumpers etc.

The GL was a step up. It added a tach, oil pressure and voltmeter to the guage cluster and stuff like power mirrors (stuff like power windows and locks remained optional, my 87 GL is evidence of that) Turbos were available in GL's but not too common

The GL-10 was the top of the line model. Nice cushy interior, digital dash, some models had air suspension moonroof, power everything, trip computer....

Thanks for the info, there's a DL 4wd for sale in my area that I was thinking to take a look at. 1987 with 57,000 miles, 5spd.

Wow, thats very low miles. Being where you are, if its not rusty, sounds like a good car (probably due for timing belts though... they COULD be the original ones)

57K is super low for any car, but definitely for a DL/GL car (I have 285K :D )