92ranga

Any advice on where to weld the 02 bung when using shorty headers? I had to install the ones below due to space constraints and am debating whether to put them in the collector or several inches below, in the exhaust pipe. Exhaust pipe come straight down from the collector for about 6" then into a 90° bend and straight out.

jimmyblue

iTrader: (11)

Those look like coated; if so, I'd put the bungs somewhere
downstream where you won't mess up the purty. Like right
below the flange, in the down pipe. NBO2s like being hot.
A wideband bung, though, I'd put a few feet further back
because those need the internal heater to have authority,
and can't be put where the gas is too hot.

92ranga

They're actually stainless not coated so no worry about messing them up. The O2s are just stock units from a silverado so nothing too fancy. I'm thinking I'll just put them in the exhaust pipes, a few inches down from the collector but before the bend.

.boB

iTrader: (1)

It depends on what kind of O2 sensors you're using. The real issue is that O2 sensors have to get pretty hot to work correctly. Most wide band sensors (like LM-1) are self heating, so you can put them almost anywhere. But most 3 wire narrow band sensors are not heated, so they need to be about 18" from the head port.

So, what kind of sensor are you using, and what does it connect to?