Inputs on a home built 318 for red light to red light fun

Check out these books, get one or get them all. Read, then wrench. Don't be in a hurry where you might miss details.

https://www.amazon.com/dp/1613252803/?tag=fabo03-20

If this is your first build, the books will help. You have the parts, go ahead and assemble it , run it, tune it. Decide now if you want to degree the cam (you probably do). Don't get into hogging out ports until you get more experience, besides how will you know what difference it will make if you don't run the engine before the grinding and porting. It seems to me you are trying to build a race engine for your first build, that's fine, but get the books and spend time reading them. Read a chapter on the crank, then go out in your shop and check/polish your crank, then read one on the block, then go hone the block. One step at a time is all. I still say with that solid lifter cam that you'll want heads, use Speedmaster or Edelbrock and call it done, however you may want to run your 273 heads just so you can see if there's a difference when you put aluminum ones on later. Alot of this we do as a journey or learning experience in a quest for more power, sometimes following someone else's recipe doesn't yield the same results.