How much HP do you lose when you add a stall?

hey guys i was just wondoring if or has anyone lost hp when they added a torque converter? i see many guys pushing around 370-380rwhp with a stall thats 3000+. correct me if im wrong but do you really lose hp when you add a stall? if you do, how much do you lose?

I think I read on here somewhere that a new purpose built high stall converter will cause less drivetrain loss compared to a 're-stalled' converter.

You will dyno lower due to the TC slipping more but, you will be faster. Speed is what you want so who cares if you don't dyno as high.

I ran 13.2 @ 105 before my converter

I added the 3200 stall, new plugs, alum driveshaft, X-pipe w/bullets (from a Y-pipe setup) and ran 13.1 @ 102. My trap speed dropped 3mph and I only cut my 60' down .1 from 1.9 to 1.8.