OP here ,
I started this thread with an inquiry about sourcing for an electric wiper unit for conversion in my '54 3100. In the course of discussion someone mentioned Ficken Wiper rebuilding. I enjoy preserving original systems and components in my modified truck , so I contacted Ficken and was pleased with the enthusiasm I received from the guy on the other end - they will happily rebuild my vacuum wiper drive for considerably less than the cost of a new electric unit. I am fully aware of the shortcomings of function of vacuum wipers ; I am old enough to have driven cars with that archaic system. That's ok by me - in fact I like it because it dates the truck. My truck will be a fair weather fun truck , not a cross country trip maker , so vacuum will suffice if I get caught on the way home. I was told that my 283 with 4 bbl Edelebrock will be compatible with the original vacuum unit. I'll get the vacuum right off the manifold , no separate pump , no reservoir.
I am quite pleased with this opportunity - I did not know that option was available prior to my inquiry here. Thanks for all the input , especially those who suggested vacuum options.
Another problem solved , at least tentatively.