Cool jamonte I am sitting down tonight and ordering an afr after dinner. I hope they have the ones to kinda match my gauges. Thx a lot . Also thanks mild and others for the advice. I'm still up in the air of using stock block or go dart. Realistically I'm gonna have 750- 800.hp. The 502 block is 4 bolt main. My Malibu I've sprayed dual stage nitrous through it before and never had problem but the way my luck goes this marine stuff would break my stuff. Just rather know if it will hold up.

You can always do a handheld one, tune it, unplug it and be done.

You'll be fine with a gen 6 GM block at that power level.

Where can I get handheld and what's a good one? Thx mild

No coolers, low boost, motors have been together for years. Thanks for the help

I would install an 02 and see what you have for a current tune as far as AFR numbers. Since they have been together with no issues, that should tell ya something. You may just wanna "fine" tune it a bit

Post number 13 in this thread I put a link to the NGK one. I also had a FAST efi one. It had dual channels to read both banks at same time. But that one is around 400 bucks. Both worked well. The NGK on is simpler, and doesn't record a log like the fast one. Innovate makes a nice one too that can be used with a data logger I believe. For the average guy I think the NGK one is hard to beat. You can calibrate it easily before use also

Joe. Awesome insight man. I have a question. What is boost referencing a carb? I've read the term on here but have no clue what it is.

Basically the powervalves open when in boost instead of a specific vacuum.

Basically what Icdedppl said. On a N/A aspirated engine, the carb is mounted on the intake manifold, and the power valve reads this intake manifold vacuum. When throttle is opened, manifold vacuum drops, power valve opens.

With roots supercharger, the carb sits on top of the blower. It no longer can read intake manifold vacuum. It reads whatever the vacuum is at the top of the supercharger. In certain scenerios, your intake manifold will see boost psi, but your power valve is still seeing vacuum.

Boost referencing is simply modifying the carb so that you can hook an external vacuum line from the carbs PV circuit, to the intake manifold. This way the power valve only sees manifold vacuum/boost.

joe very good info ive got the 02 bungs in my tail pipes ill be doing some testing this spring good seeing you on my b day