After adding a stereo to my car (1965 Valiant 170 slant 6 with power steering/no AC), the power to said stereo cuts off when the brake lights come on, and the RPM's fall under 1100. The stereo comes back on when the I let off the brakes, and RPM's come back up. I believe the alternator (original 35 amp) is not enough to power the stereo along with other electronics. So, I am wondering if a 45 amp alternator would make a difference? If so, the 45 amp has a two groove pulley versus the original that has a single groove pulley. Would the two groove pulley be compatible? Thanks.