what size alternator
 

I have a 79 Trans am 400 with electric fan, fuel pump and good stereo. the 65 amp alt. isn't working up to par. I was thinking 100 amp alt. any ideas.

i have a 79 f/b, 428 engine:

MSD 6AL box
holley blue elec. fuel pump
spal 30A x 2 elec. fans
elec. vac. pump for brakes
a ton of gauge lights (not much amperage though)
4 headlights (as all 79 f/b's have) and all those brake lights.

I run a powermaster 100amp alternator. point of this...? 100amp is plenty.

Fb428 thanks, at a stop light the volt gauge goes to 11 volts