Need to recap my Classe Audio DR-8 Amps - need suggestions

Sorry to hear about your woofers. I would put a voltmeter on the amplifier outputs and see if you have a significant DC offset. That is something that has the potential to take out woofers. If you have DC offset, it could be from something internally faulty or it could just need adjusting. Pretty straightforward procedure, put meter on outputs and tweak pot until it reads 0 +/- 1mV. Here is the procedure from the DR-8 service manual: https://www.hifiengine.com/manual_library/classe-audio/dr-8.shtml
Looks like same procedure as on my DR-10 which I have owned since new. I have no indication that my caps need replacing and I have been using for some 27 years now.

This information is for Dave (dlcockrun).   The service manual for your DR-9 is located here:   https://www.hifiengine.com/manual_library/classe-audio/dr-9.shtml  The service manual identifies the transistors as MJ15024 and MJ15025.   As stated they were manufactured by Motorola, but now are manufactured by ON Fairchild.   All the other components are marked on the component as you stated.   I would find it highly likely that the preferred sound is not due to difference of transistor manufacturing, but in the transistor bias.   The procedure for adjustment is in the service manual.  Fairly straightforward;   however, be very careful with your probes, get a good clip lead on the emitter when powered down.   Do not use a normal DMM probe that can contact the rail voltage while on the emitter taking out the entire bank of transistors... unfortunately, I am talking from experience (smile).   You could even measure the bias of the preferred sounding amp to see if it matches the recommended bias of 18mV.    If this is not your forte, you likely could find someone locally to perform this function for you.  Just an idea.   One other note, the DR-9 manual (from provided link) is missing a page of the power output transistor section.   The drive section (shown) is what is adjusted is identical to the DR-10 (that service manual schematics are complete) and I find it likely that the power output section is also.