Yes, they are relatively the same except the strut body is a bout an inch+ longer on the 71831 than the 171831 model and the 171831 strut body is right at one inch longer than the stock strut of a Tracker/GV.  Maybe the longer shaft would be more durable. Who knows?  The Oldsmobile Cutlass model weighed around 3,300 pounds so the weight between the two vehicles is similar... within +300#s or so.

I'm now running the 71831 struts they are smooth on the road. I had to slot the bottom hole to get them to fit. I flexed the suspension  and had about 1 1/2" to 2"  of strut left so ti was not compressing the strut too much.

the struts from a Cutlass Supreme are probably the rear ones these cars do have a 4 wheel independent suspension.  The fronts use coils on the strut body.  The rears use a fiberglass leaf spring that mounts in pockets at the bottom of the suspension knuckle. meaning the rear struts have no provisions for putting the coil on the strut body.  Just my 2 cents.  I would like to try it on my tracker when I get Jeff's lift

I already tried this about 4 years ago and they are way too soft the internals are far too weak. I also went through the monroe strut catalog and could not find anothet suitable donor.

If those 71831 struts are for the rear of the Oldsmobile, that would make sense.  There is a heck of a lot more weight and pounding on the front end.