EQ head build + home porting advice sought

Everything I saw on porting the EQ's said the guide can be cut down a lot also, because it's so long.
You want to be careful in that wall area that protrudes into the port in your last pic as I remember them saying the cast is a bit thin there, and there was also a discussion about the roughness of the cast there being a good thing for atomization and has very little affect on flow.

You are correct about the stock rocker being totally usable, but you probably saw that there are a ton of choices in the Chevy bin for roller rocker alternatives (most of which you have to change the stud for)
I run a 214/224 @50 with .512 regrind Magnum cam from Oregon Cam Grinders and didn't even have to change the factory hardened pushrods or guides.
Also used the Hughes springs and retainers you are using.
Stock bottom end at 9:1 and runs fine on 87 pump garbage. :D
I run a eddie dual plane performer and a 600 eddie carb, but with the air gap manifold and a 750 Holley they say 400hp/415tq @3,500 is the norm with our block and heads.

Ran that thing to 6k yesterday and it never quit pulling with untouched ports.
I have hiway gears though so I was near 100 in second gear, and have a 5 speed automatic overdrive.