heat sinks and alt repair qiuestion

[rbraun at mail.enter.net]

The alt on my '91 GTA just puked, it's a CS-130 105 amp, I got it all 
apart and the way I see it the diode package grounds to the case 
through the heat sink compound.  I'm thinking the poor ground thus 
created is adding to the heat of the diode pack and helping to 
cause them to fail.   Should I leave heat sink compound off 
entirely?, or at the end where the output term connects? or add a 
ground wire?

The base of the d-pack is 3/32" thick copper plate which mounts to 
the alum case of the alt.  Would a copper to alum. mount 
transfer electric and heat better with or without the heat sink goo?

Any EE's want to give opinions?

TIA,
Randy Braun     rbraun at enter.net
91  GTA
82 Firebird