Dana manifolds sell the O2 sandwich plate which goes directly between the manifold and riser (at the collector pretty much). Is this ok?

Yes. I run a similar setup (not Dana manifolds) and it works fine.

Innovate offers an O2 heat sink which also provides excellent protection against reversion if you're forced to install near where water gets introduced. It was primarily designed for high temp applications but due to it's design works well in marine exhaust from my experience. It allows for exhaust gas sniffing with a directional input hole pointed upstream which helps keep any moisture from coming in contact with the sensor.

This product might be worth a look. It's tough to find as it's buried way back in their website.

http://www.innovatemotorsports.com/x...cat=250&page=2

The Dana o2 sensor block for the Dana Flow Torque exhaust manifolds keeps the exhaust seperate for the four cylinders and the exhaust does not combine until after the riser. The sensor block comes with only one hole drilled and tapped for an o2 sensor so you only sense a single cylinder from each bank. I drilled and tapped all eight on mine.

http://www.danamarineproducts.com/Pr...3-a0a44133bd9c

That's a good point. I forgot the Dana block still isolates the exhaust at that point. I'm using an open spacer on top of GLM manifolds and stock stainless risers so it's looking at a mix.

[ATTACH=CONFIG]527871[/ATTACH]Can i install o2 bung here for testing?

Too close to the collector, I don`t think you`d get good reading there.

Will it work?

Yes

Is it ideal?

No

If it was more in direct line with that one primary, I would like it more being that far "up" the collector....but its kinda just hangin out in the middle there.