Today, dollar for dollar, is the 318 faster than the 340 ???

So at any rate you spend $1,800 on getting your 318 rebuilt to your specs in machine work , what do pistons cost $400? So with black Friday sales the intake, cam and carb would still be in the $3,000 area corret?

Wrong. Oil pump? Timing set? A new damper of some type because a 40 year old unit is worn out. What about rings? Now add in those heads. And the intake manifold. And a decent carb. Your 3k budget is in the rear view mirror.
I can see that some of you won’t admit that 3000 2021 dollars won’t build anything. And some of you admit you still build stuff like you did 35 years ago, and brag about it. That is a sad testimony to me. If you’ve been doing something for 35 years and haven’t found a way to improve what you do, you either can’t do it or you think you’re so good it’s good enough.