Tim, start by asking yourself, how many miles will you really drive the car each year. Not how many you would like to drive it, or how many you dream you will drive it, but how many you will REALLY drive it. For most people, it's less than they plan or expect. Based on that number and 10 years as a number grabbed from thin air, that's the life you need from the engine. Really, just about anything you get, if done with quality parts, will outlast you.
Now consider how much fun you want to have driving the car. The bigger the engine, the more fun you will have. Anyone who says different has a small engine.
Most everyone agrees that the cylinder sizes to use are 90.5 and 94, and avoid the others. As for stroke, longer is better cuz, as a generalization, it makes more torque. With a standard case I think you can go up to 82mm without having to clearance the cam. 94 x 82 is 2275.
Power in an engine is made with compression and efficiency. So, for the same size engine, you get more power with: a bigger cam, ported and polished heads with good flow at low vacuum, a higher compression ratio, good carbs.
I said heads that flow at low vacuum because that is where you spend most of your time driving unless you are racing. Then you want heads that flow at high vacuum.
The problem with higher compression ratios is you need to run higher octane gas, but higher compression ratio is cheap HP.
Don't go for carbs that are too big or your engine won't run well at anything other than wide open. Get carbs that are the right size, and then just tell everyone they are 48s.
My opinion is worth what you paid for it.....
