No, the pump for the '87 has been out of stock for more than 10 years probably. I have a spare, but I'm keeping it.
Unfortunately, most '87 specific parts are no longer available. The seat on yours isn't correct because they ran out of them long ago, as well. I can't offer any sources, but surely, someone out there is parting an '87. You just have to be vigilant.
In the mean time, you could put a cheap used OEM from another year on it, with the stock relay it would work. You'd just have to rig a step-up for the hoses. The early ones had smaller ports. The one you have now may be small too. It looks like there are hose clamps on it.
I just looked on eBay and didn't see anything cheap enough and there's even a rusted out aftermarket one they are claiming is OEM, so you have to be cautious. Where are you located?