Have opportunity to buy BHK 300's or Pass Labs 250.8 for my Thiel 3.7's- thoughts??

I have a Pass 250.8 pushing my Maggie 3.7i never a problem great musical sound.

They almost always stay in Class A unless I really crank it.

I think you'll be very happy with Pass equipment.

Sorry both deals fell through — that sucks. As another potential option, McCormack and Thiel have always made for a synergistic pairing, and there’s a nice DNA-1 on USAM for around $2295 that’s probably negotiable as it’s been listed since mid June. It has SMcAudio’s “Silver Special” upgrades I’m not familiar with but seems to incorporate many of his latest mods. You could ask him what it has and what’s left that could potentially significantly improve the sound further (Gravity Base is likely one), and even after doing any remaining mods you’re still probably around $4k all in and you’ll have one great amp. Power shouldn’t be an issue as it doubles to 300Wpc into 4 Ohms and puts out 500Wpc into 2 Ohms. Of course since it’s already got a significant amount of their mods you could just enjoy it as is for a while and upgrade later if you start to get “the itch,” and it’s nice to have the option of getting even more performance down the road. Anyway, just another option to ponder, and best of luck in finding a great amp for those great speakers.

FYI; OP nearly 4 years ago.

DOH!!!  Thanks @unsound.  What an amateur mistake. I feel shame. 

Have you considered Audio Research? I used to use a Ref110 with Thiel 2.7 with very good results.