VSS question too

[Jake Sternberg]

I'm installing a 1982 crossfire injection system onto me 1979 chevy van.
i'm also installing a 200R4 transmission with lockup torque converter,
which the ECM from the crossfire will plug right into.

my van doesn't have a VSS anywhere on it; the cruise control that came
with it from the factory used one of those in-line speedometer cable
pieces of junk.  I'm removing that and replacing it with a modern
(1985 chevy van) cruise control setup, which uses a pickup on the
speedometer itself.  I'm using the speedo from the 1985 van too.

there's a pickup in the speedo itself, and a yellow plastic box a little
bigger than a butane lighter which connects to it with a short wire.  the
little yellow box has a three-conductor card-edge connection on the side
where the cruise control connects to it.

Does anyone have any idea if i will be able to use this for my crossfire
ECM?  it expects the 2000ppm DC signal.  the 1985 van was carbureted.

Thanks,
Jake