I don't know if this will be of interest to anyone, but after trying out at least 5 different glasspack and muffler combinations I ran across a muffler at JC Whitney that's of the same design as the original CR mufflers except that the inside tube ID is 1 3/4" instead of the original 1 1/4" of the CRs. I purchased a pair for around $25 each and installed them a week ago.
The sound is beautiful!....They're mellow, quiet and give off the sound reminiscent of early muscle cars with turbo mufflers.....that plinky sound of headers combined with a low sound of big cubes.
As far as power loss....I really can't tell. My engine has more than I have ever been able to use effectively and I honestly can feel no loss at all. If anything the engine seems to be a bit more responsive on the low end, perhaps due to the extra backpressure, but whatever the difference is it's worth it..at least to me. Conversation at driving speeds can be at a normal level and the only time you really hear the pipes scream is when you're really on the gas...and then they sound great.
Anyway....if anyone was wanting to try them I thought I'd let them know that they work well and sound good.
Bill