Engine planning 101

So what started all this is I'm working on my plan and I'm trying to work out any issues before I start buying anything. That way when I drop the block off I can tell the machinist exactly what I want and know what I'm getting. So I started with the intended purpose of the car
1)Street car
This car is has a an automatic transmission 999 torqueflite and 2.76 highway gears
So I know I want to run on pump gas so that is where the questions start. What scr/dcr can you effectively run on pump gas? There seems to be alot of opinion with no definite answer.
Moving on...
I'm reading my book (Larry Sheppard how to hot rod a small block mopar) and imo this is the worst book ever written. It is so jumbled with little factoids but no explanation or definition. So anyway I'm reading about valve to piston clearance and it tells you how to check it but again in order to do that you have to already have the engine assembled. So how can you plan for pistons and cams without knowing this information beforehand?


Everything I asked you, that's where I start.
You're talking about building around an octane limit 1st. Point being ... have a target power range and set a perimeter in which it must function...then figire out which end you want to be on... safest or ragged edge.