Call Jim at Rewarder Headers. He has his own version of the Bassett T-valve. Essentially the same thing, he can answer any questions you have about it sticking etc. He is very honest and Headers for boats is what he does primarily. He is a great guy and if you end up driving to his shop take an interest in the Woody Willy's he's got in there... It's bitchin. Rewarder's number is 1-805-445-1015. I have Jim's cell number if you need it.
I ran Rewarder's T-valve without a hitch and my old Caribbean was on the water 2-3 times a week since march. He gave me a much better price than Bassett too, without the Bassett attitude.
P.S. Rewarder makes their headers in the good ole USA in Camarillo, CA. It is my understanding that a lot of Bassett's stuff is made in Mexico...