More Hp from a RHS 360
The heads flow well, I would not spend the money there. A 750 is more than enough carb for a 360. The intake is on the right track, but and Eddy AG would be better.
If you really want to make power, upgrade to a solid roller cam and shave the heads to get 10 to 1 or more. This is the cam I would use in your 360.
https://www.lunatipower.com/CamSpecCard.aspx?partNumber=60432
I would bet you would be close to 500hp.