if you braze the alum all yourself using HTS2000 alum brazing rods
on well roughened stainless brushed surfaces you can save a good
penny from asking a pro to rape you.

I did my alum pipe based bumperettes with different alloy brackets
and also repaired alum inlet manifolds with success.

Prob 400 aud all up is possible this way. The other way is harder
but I also did arc welded inlet manifolds for bike carbs that worked
well and for boost, plain steel is overlooked.