3 wire GM sensor, sequential injection

[TMatthe at aol.com]

Anybody have the schematic for the GM 3 wire sensor? I have headers on my 84
Monte Carlo and I'm having trouble with the sensor cooling off and I want to
wire in a heated sensor. Plus, can someone explain sequential injection? I've
heard that there are a few different types (phased? and true?) I understand
sequential inj. is fired in firing order, and I'd like to set up a sequential
injection on my 69 455 Firebird, but since I have no experience in sequential
inj (but plenty with batch fire) I would like to use the minimum amount of
sensors specific to sequential injection. Any suggestions/comments/ stories
on how someone else put sequential injection on a dinosaur?
TIA,
Tom