My doomed 408 build

Was the same carb and jetting used for both tests?

I was looking through some of my dyno sheets and I found a test on a 410 with a mild small-ish solid roller, that I didn’t run, that had bsfc numbers almost as bad as the ones on your second test.
On the test here, the carb was way way too rich....... so the power was down, and the bsfc up.

Did you only get one page of data for each test?
The air flow data is likely on a different page(if the air flow turbine was used for the test).