Way rich if it was dynoed with dyno headers ....you're on the right track now pulling fuel from it. I'd be looking for around 12.2-12.4 wot. Your prob easily in thr 10's if not richer.

The real question is why didn't they let it off the dyno that way? There's no way it was near max hp with that AFR.

I think they came off the dyno that way because the power numbers were pretty much the same using either carb according to the dyno sheets. We were all surprised to see same power numbers with such variances in A/F and other figures.

I'm quickly learning with this adventure that trying to save a buck and buying used stuff for some things is pointless. When I do decide to get some new carbs should I stick sith the Holley marine 800? The other option I keep reading others have used is the holley 830 but that's not a marine carb. Or do they make a marinized version of whatever you want?

Be careful, most 830's (That I know of anyway's) are for high output small blocks - as in 350cid size racing small blocks. Trying to tune them in correctly for big blocks can be tough. Does not usually turn into just replacing jet's sort of deal.

Thanks for your input. I'll keep this in mind when shopping and talking to others about it.

I don't believe there is anything wrong with your carbs. You just had a lazy dyno guy not tune you engines like you paid him to do. Anyone letting an engine off of the dyno with 8-9 AFR's is going to cause more harm than good. (your AFR's correlate to your bad BSFC #'s) You are going to be washing cylinders down with gas and contaminating your oil. I believe you are on the right path and there is power left on the table.

My $0.02

IMO, Even the A/F numbers on the right side (with their "in-house" carb) look to be on the rich side if he was running it with dyno headers. Depending on the exhaust you run, when you factor in the added backpressure of the marine manifolds or headers, water mixing in, and any kind of muffler tip you may be running, you can expect the actual A/F numbers running in the boat to be close to a full point richer. You will also probably have much warmer, less dense air under your hatch. Did he dyno them with the same flame arrestor that you will be running?

When I showed up for my #1 motor session I did bring along a flame arrestor, that dropped the power down about 10 points across the graph. Not going replace carbs just yet, first going to get wideband and see if I can get it reasonable with what i have. For now i'll reduce my secondaries back down to 85 jets.

Just for comparison I had 462's with dart 308 heads a small comp xm272 cam with air gap intakes and the same hp 500 carbs I burned them down with 75 front 92 rears ended up with 84 squared and no problems