There is probably a number embossed on it. Or you could try a gm onlune parts store. Or you could call your local GM parts department.

 

Looks like 12626029. Supersedes old part number 12622037.

 

At those prices I would investigate fabricating one. A piece of PVC pipe, 2 end caps, a couple of hose barbs.

I did see it on eBay for $38.

 

Jumping into the WABAC to post the actual function of the vacuum tank. It is used only on front wheel drive turbos, it is intended to help the bypass valve operate smoothly. The valve might usually be alright without it, just needed under special circumstances.
I don't know what makes front wheel drive different.

 

Thank you !

 

ZZPerformance ebay store

Only about $30 plus shipping