08-24-15: DoakYep, This mirrors my experience rolling BT CV181 in a MW Transporter years ago.
I suggest, even urge, you to invest in a pair of Black
Treasure CV 181. I've used them in amps, i my current
preamp and IMO they beat my stable of some of the "best
of the best" old stock 6SN7.
I have several friends rolling them in their VAC 450 and Phi200 mono amps.