Guess the hp/torque on street 589ci wedge

572-13 heads with little or no porting don’t flow very well at all....... especially below .500-.600 lift.
So, with a .620 lift cam you’ll have a combination of a big port and low flow, resulting in low air speed.
The low CR isn’t helping to get things moving either.

Then there’s the dyno variable.
I’m sure I could find two dynos where that same motor tested on both could vary 100hp.

I wouldn’t be expecting anything too special out of it here....... but I have no idea what you guys got out of it there.

It wouldn’t surprise me if the tq number was higher than the hp number.

I’m not sure what your combo there is, but the “typical” BB Mopar 588 is 4.50 bore x 4.625 stroke.