My experience with the BMF 18* stuff and even the BBC stuff is
they are rather "light" castings, .. not nearly as strong as the
Edelbrock pro port style casting myself, Chapman and WeldTech use.
The rocker threads are few and fairly thin, .. just not a very beefy head, .
I wouldn't use them on a turbo project.
They flowed about 20 cfm less then advertised on my bench but with some
hand porting & tuning came around close to the advertised numbers.
There's better 18* heads in that price range, . .
if you are going to use a turbo or heavy NOS I'd use an 18* before
I used a 15* or lesser valve angle.
The primary reason the flatter valve angle stuff like my 12* wedge head
is for the small chamber and taller port, .. but you don't need that
with a power adder, .. and the small chamber could be a problem.
Curtis