The 1960's series 172's tracked closely with the 150's of the time in terms of equipment. I had a 35 amp generator & last year upgraded it to a Plane Power 50 amp alternator and solid state regulator. Plane Power guys was very easy to work with (unlike Jasco who seem uninterested). And, check to see if the Jasco doesn't require you to install an airscoop to keep it cool. I had to source a 50 amp gauge and found a pretty good one at a salvage yard.
I couldn't be happier with the PP alt. Solid voltage on the bus (unlike my generator) and all the power I can use.
Great upgrade, you save some weight too. It helps to have someone who *really* knows their stuff w/ electrics. I had Titus...'nuff said.
