Here's the link to their website that shows the bypass pullies available (as well as many other products you might not think were available aftermarket).
https://www.dormanproducts.com/cgi-b...MP319681hwrap1
For reference, the part number for 89-96 Lumina's with the 3.1 is 34197. I've installed one on a Buick Century, and the only issue was the mounting bolts. The OEM compressor had threaded holes, where the Dorman part was straight through, so I had to get longer bolts and nuts because the factory bolts weren't long enough to go through the Dorman bracket and get a nut started on. Other than that, it was a troublefree install, and it's woking great.