Did any of you horsepower calculator guys ever use this

I tried 2 more combos, which were both built out of the same short block.

One was smaller heads and a SFT cam, the other used bigger, higher flowing heads and a SR cam.

The small head combo showed just over 50hp low and peaking about 600rpm low.

The bigger head combo was closer....... down 31hp, but the rpm was correct.

From my perspective....... it’s pretty useless.

I tried 2 more.
The combo these types of calculators really doesn’t like is a std port BBM stroker that doesn’t have heads with fantastic flow numbers...... and this one is no different.

Pump gas hyd cammed Ede headed 505 is 76hp low.
Pump gas solid cammed Ede headed 493 is 105hp low.

I even tried a very normal SBC 383 combo with decent heads, CR, and a SR cam......and that too was off 47hp.

It’s probably the worst one of these things I’ve tried so far.