When my friend went from an auto trans to a manual in his GTO stocker it picked up about 5mph in the 1/4, which shows an almost 60hp gain in a trans swap.
One takeaway there is........ the calculator results will only be as good as what the weak link in your combo is.
His current Firebird Stocker will outrun the calculators in any kind of normal air.
When you really want to know how much power your motor makes, you bring it to a reputable dyno service.
If the car doesn’t run what it should, based on the power numbers....... start working on the car, and leave the motor alone.
HP = (MPH ÷ 234)³ × Weight
That works out fairly close for speed compared to the Moroso chart.
A couple months ago a friend of mine bought a used bracket race engine.
Brought it to the dyno, it made 728hp.
A couple of weeks ago at LVD it went 9.10@145.88 at 2915lbs.
On the Moroso chart the ET shows 734hp, MPH shows 695hp.
If I use the above formula for speed it works out to 706hp.
