Disappointing dyno results

jawbone said
Hi ch1ll. Regarding Carter AVS. Dyno operator only had a lager Holley which yielded similar results. He will receive 600cfm Holley for pull tomorrow if weather permits. Humidity is currently high. Operator does not have any replacement jets or metering rods. The Carter I had rebuilt was stock unit for 68 or 70 340 4 speed application. Can't remember which. Would only think jetting would be correct.

Cam is from Camcraft. I know, you never heard of them. Wish I hadn't. Only looking to make stock horsepower. That's all I can expect using stock engine components.

Jetting is never correct unless it's been tweaked for current conditions. Yes, that's over over-statement, but it would not be abnormal to see AFR vary from nominal when the cam isn't exactly stock and the exhaust isn't stock, and the air filter is removed, etc. Every carb needs fine tuned to conditions and equipment.
It's a shame the dyno guy doesn't have some AVS parts on-hand to help out, but it sounds like you can rule out the carb as an issue with the 600 holley.