Horsepower Estimate?

Yes but mph and weight will tell you this
at that mph at that weight the quickest you can go is X et
nothing is more accurate then that
period
That is what the dc chart that was posted shows 98 mph gets you 13.0 if traction gearing and everything is perfect
few and far between can run the ets for those given mph


Claiming a time slip is the most accurate way to determine horsepower is just not true.

The chassis could be bending like a paper clip. The converter could be wrong.

The tires could be junk and maybe, just maybe the shocks and suspension could be whacked.

A time slip is only as good as what you are working with, which is no different than using dyno numbers.