Mark,
Parts are here from Mouser with the 8 power transistors. After installing the new transistors and checking for shorts to the heatsink, should I do any other precautionary measures before powering up. Like turning down the idle current currents a bit? Or should they be okay where they were last set? Don't want any magic smoke.
With new outputs (or ANY work on the amp) you ALWAYS ZERO THE BIAS before applying power.
Always bring it up on a light bulb tester (with bias set to zero after amp work) first. Then do a PRELIMINARY bias adjust to TEST it with the dim bulb tester, in case turning UP the bias causes a problem. BUT using the dim bulb causes a brownout condition, that will mean that if the bias was set while it was connected to the dim bulb tester, the bias will be WAY TOO HIGH when plugged directly into the power line.
So on the dim bulb, turn the unit on, set the bias on a channel - JUST to see that turning up the bias doesn't cause a FAULT, and then turn the bias back DOWN to ZERO. Then do the same for the other channel. The bulb WILL probably get a bit brighter as the bias is turned up, the unit IS drawing a bit more power....
In your case, once the dim bulb bias is set, read the voltages across ALL of the emitter resistors for that channel, making the voltage readings across the individual resistor's leads, the readings should be almost identical. If not, stop and post. If they are, zero the bias setting in preparation for doing the other channel or removing the dim bulb tester.
THEN take out the dim bulb tester and plug it straight into the line.
THEN dial up the correct bias. The position the pot ends up in with the correct bias will be lower than the dim bulb set position.