Multifinction sensor

["L. Scott Oliver" <SOLIVER@gcwf.com>]

My '87 5kCSTQ has the typical dying multi-function sensor.  I
ordered a new one from GPR, got ready to put it in, and noticed it
only has three contacts, though I have four contacts and four
wires going into the original.  GPR says this part supersedes the
original.  Anybody been through this before?  Is it something
simple (e.g., ground is now taken from the block instead of a
wire)?  Is this the right part?

TIA!

--Scott