Shaking

I have a problem with a little bit of shaking while my heater is on. I have a 1999 Silverado 5.3 L. V8 about 75,000 miles. Doesn't shake when the heather is off. Also when i accelerate, I can hear a ticking type noise from what seems like the floorboard, drivers side, near front of door area. If anyone could help that would be great.