I have been thinking a lot on this subject.
A lot of reinforcements I have seen does not really stiffen anything (generally speaking). They tend to attach the inforcements to some weak flexing sheet metal. Looks nice but doesnt really do much.
My thinking is not finished yet
, but I have one idea.
The upper control arm´s mounting is really nothing more than a rather thick piece of stamped sheet metal and it flexes inward.
It should be a good idea to extend that piece of metal upwards (with a boxed shape), following the curvature upwards in the enginge compartment all the way up to where you mount the fender.
This way you make your own "strut towers" and can connect them with each other with a ordinary type strut tower connector.
-76 Monza 2+2, 400", 8.8 rear ... if Ispell funny sometimes, Its because I´m Swedish and Hauge is a Norwegian name