Is injector #3854518 no longer available for purchase?

The injector 3854518 is indeed obsolete.  I haven't been able to find anyone that
has one of these or able to recommend a replacement.

However, Mercruiser had a 1997 7.4 MPI that used an injector with a part number 805225A1.

This number 805225A1 is also obsolete from Mercruiser, but I do have four new of these in
my stock.

I believe, but I can't promise this, that you could use this injector.   If you could give me all
of the numbers on your injector I can compare them with the numbers on my Merc. injectors.
I think the same manufacturer made them for both the Volvo Penta and Mercruiser version.