ORIGINAL: burtona
I used an HP 61 in 1972-73 time frame. Replaced a Webra 61 Black head with it. Replaced the HP when the Webra Speed came available. Replaced the Webra Speed when the Rossi became available. Each was a noticable step up in power.
Thanks Burtona, very helpful to see the progression in power. A Mach 1 or Nutcracker might be right for the HP.61.