[Kilroy]

Okay, for all those wondering about whether they have a GL or a GLS, I found the following online:

1999 Oldsmobile Alero GL 2dr Coupe Available Trims
Trim Information
GX 2dr Coupe
Horsepower:150 @ 5,600 rpm
Torque:155 @ 4,400 rpm
Transmission:4-spd auto w/OD
Curb Weight:3,026 lbs.
Fuel Type:regular unleaded
Compare MSRP:$16,355
Market:N/A
Invoice:$15,292 Engine:2.4L I-4
Fuel Econ.:22/30 mpg


GL 2dr Coupe
Horsepower:150 @ 5,600 rpm
Torque:155 @ 4,400 rpm
Transmission:4-spd auto w/OD
Curb Weight:3,026 lbs.
Fuel Type:regular unleaded
Compare MSRP:$18,385
Market:N/A
Invoice:$16,822 Engine:2.4L I-4
Fuel Econ.:22/30 mpg


GLS 2dr Coupe
Horsepower:170 @ 4,800 rpm
Torque:200 @ 4,000 rpm
Transmission:4-spd auto w/OD
Curb Weight:3,026 lbs.
Fuel Type:regular unleaded
Compare MSRP:$20,975
Market:N/A
Invoice:$18,982 Engine:3.4L V-6
Fuel Econ.:20/28 mpg


GX 4dr Sedan
Horsepower:150 @ 5,600 rpm
Torque:155 @ 4,400 rpm
Transmission:4-spd auto w/OD
Curb Weight:3,077 lbs.
Fuel Type:regular unleaded
Compare MSRP:$16,355
Market:N/A
Invoice:$15,292 Engine:2.4L I-4
Fuel Econ.:22/30 mpg


GL 4dr Sedan
Horsepower:150 @ 5,600 rpm
Torque:155 @ 4,400 rpm
Transmission:4-spd auto w/OD
Curb Weight:3,077 lbs.
Fuel Type:regular unleaded
Compare MSRP:$18,005
Market:N/A
Invoice:$16,475 Engine:2.4L I-4
Fuel Econ.:22/30 mpg


GLS 4dr Sedan
Horsepower:170 @ 4,800 rpm
Torque:200 @ 4,000 rpm
Transmission:4-spd auto w/OD
Curb Weight:3,077 lbs.
Fuel Type:regular unleaded

Sooooo, it would seem from this, if you have a 3400 engine, you have a GLS. Now this is for a 1999 Alero, but I would assume it is the same for all years.