Don't let's all forget one of the challenges of any fuel injection retrofit, whether throttle body or port, is installing an oxygen sensor. It's easy if you're running cast iron exhaust manifolds (or at least
the rear half of a manifold, on slant-6 applications), because for most of us there are manifolds made with O2 sensor ports, intended for '81-up versions of whatever engine we're working on. You want a heated (3- or 4-wire) O2 sensor. It gets trickier if you're running headers, because the O2 sensor wants to be up close to the exhaust ports
and looking at exhaust from as many cylinders as possible. Easy with a manifold, hard with headers; you wind up having to choose between watching only one cylinder (close to the port) or being far from the ports (watching multiple cylinders at the collector). If you have to go with a far-from-the-ports location, wrap or coat the headers to keep the heat inside and use an O2 sensor with a high-wattage heater.
