> Yesterday I tried both of them. Both appear to screw onto
> the drain opening OK, but both of them have a slow leak. Has anyone had an
> experience with this that they were able to resolve and would be willing to
> share with me? Please p-mail if you do!

I just did the same thing, bought the 2 caps, not knowing for sure which was
which by looking at the BD site. It turns out that there are 2 different thread-pitch
sizes, and mine is the wider spaced pitch, and it works fine. I could tell by crawling
under the van a looking at the drain pipe threads which cap would work.

If you put both caps on, you may have altered that thread pitch just enough that
using the larger-pitched cap (I also have an '87) that it now leaks a little. I'd
suggest addiing another rubber gasket inside the cap to allow the cap to be
tightened a little more, appllying so much pressure to that new gasket, that
the drain pipe can't leak. Both of the caps I got from BD had rubber gaskets
in them. Take the one out of the cap you don't use, add it to the cap you will
use so that there ar 2 in there, and see if that does the trick.

bob