Here's a pic of our homemade shield, Don't know if we actually needed it, but....
Joe
I stand by my 15 times previous comment. That being said, IMO it would seem best to keep heat away from actual cylinder first, and your DIY heatshield seems like it extends in addition to far above the manifold heat, and the extra conductivity of alum might work in your favor and be an inherent heat sink to the lower half of the alum shield, especially being its vertical. Meaning, don't change anything.
FWIW, I use Andy's shields on my cars. for decades?
