U.S. Amps 2000X - Bias Issue / Adjustment?

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I've taken the two down to approximately 2.5k with no discernible increase in idle current, and almost no change in voltage on the other side of these resistors. Should I go farther? I tested my current meter just to ensure it was still functioning properly, several other amps all read between .5-2 amps idle current; so I would be lead to believe it is fairly accurate.
 
I actually took the board out of the chassis, I should have gotten more measurements beforehand but I believe I recall it was only around +/- .6v if not less (from approximately +/- .5v) on the other side of the resistors. There was still no or minimal increase in idle current. I wanted to ask, as this amp seems to use mica insulators and about a gallon of thermal paste, am I able to replace this setup with anything? For example ideally kapton tape and thermal paste (as seen in a few amps such as the Lanzar 4001D), or possibly silicone insulator material? I'd prefer to go that route permanently, but even temporarily while testing would be nice.

To clamp the transistors down while testing I would also like to use rather strong spring-type clamps to hold in place a rail of aluminum down each side, allowing for easy removal and decent pressure application, if this would be a viable/reasonable setup.
 
Okay. Well, I tried it at ~2k to measure, and it started pulling 0.5v at idle, but then the two resistors got hot and smoked a bit. I pulled the remote and B+ immediately. They didn't completely burn out, only got a bit out of spec, and I replaced them, but am afraid to go any further on my own from here for risk of damage. It still plays just fine, though, so that is good. Where should I go from here, if you don't mind helping a bit further?
 
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