Re: voltage flucuation
I'd replace the alternator belt if it's been on the car for a few years. It's possible it starts slipping and gets hot at higher RPM, and takes several minutes to cool off and resume gripping the alternator pully when you're babying it. Next time it acts up, shut the car off and BRIEFLY touch the alternator pully. If it's REALLY hot, you might just need a new belt.
69 RS, Hugger orange/black, Deluxe interior, Sony AM/FM/XM/CD, PS & PB. 355, forged pistons, Eagle rods, balanced, Iron Eagles, 9.4:1 CR, .038 quench, XR270HR Cam, Z28 intake, FAST-EZ EFI 2.0, Thorley Tri-Ys, TCI 700R4, 2400 stall, 3.42 posi