Late 80's FWD Buick's V6's have them .... there's two versions ... one with the vent hole where the TTA have it (facing the intake) and another version with it on the short side so would face the firewall if installed in the TTA.
They are getting harder to find ... but they are still out there ....
At the same time I would grab the washers and acorn nuts as spares ... and you might want to grab some of the studs holding the covers in place as well if you need to modify some one day for roller rockers ...