Not looking to slow it down with the valve body. Just don't want to speed it up any.Why are you looking to do this in the valve body? Can you not use an adjustable button?
It is a TCI full tree brake with the spring.I missed #6
I’ve never seen a problem with it being an aluminum valve.
Not that it couldn’t happen.
Yes a steel one would work if it were the problem
I would ream it first then make the spool to fit.
Is it not going in or coming out?
And it could be for other reasons.
Brand of T/Brake?
So sounds like my prognosis is on target.You can easily make a steel valve and lap it to the bore, don't need much clearance. Cost of racing what it is I sure as Hell would have been into a different V/B by now. The piece you are working with is probably older and far from the best quality machine work. Long ago I puttered with aluminum hard coated valves and had the same kind of experience you describe.