i own a 1978 120y coupe A12 but require a higher output alternator .haynes manual says
origional is hitachi LT 125-06 (25 amp)
the manual says the B210 uses hitatchi
LT 135-13B or LT150-05 (I'm assuming these are 35 and 50 Amp o/p respectively)
does anyone know of a good replacement
the higher the output the better

The higher the output the less horsepower..
This current comes from somewhere..it's not magic. This is one reason why drag racers don't run an alternator.

I'd wire up a high current ammeter, and figure out how much you need, as opposed to a number that sounds good. Are you running big spot lights or something?

Chris

about the only other thing that I can add is that any Hitachi alt. that is in that series
(LT-xxx) will plug in and wire up the same way

As rgrinder says, the 50-amp alternator is a direct bolt-in replacement for the 1200 35-amp alternator. But more than just A-series alternators fit, for example:

76-76 F10
71 510
71 520
73-79 620

thks guys this will help yes i will be running thirsty spots two pairs that draw close to 20 amps and will require more electric power when i get a nice amp ps the origional alt was 25 amps untill i cooked the diode pack
opps i should have known better

i run a couple of large light force spotties

i found an ea falcon aternator is perfect, they have between 75-85amp output

when mounted the pulley is the same size as stock and in the right position, i actually have a quick diagram of the mounting in my photo album

but im thinking of putting a larger pulley on as it does suck power out of the motor when lights are on and i think im over revving it past its efficiency anway

BTW - it only slows the motor when you are actually using a lot of power out of it as this is what creates the drag, so if you get something too good its not gonna be any worse cause your not actually drawing that much power out of it, i think the larger the amp out the better because the design must be more efficient and therefore when your sucking the same output from it or another lower rating one you'll be creating less drag using the better one

anyway, you should be able to find an EA falcon in a wrecker somewhere to source the alt easy enough