[blykins]

What's your budget?

A 390 with a 428 crank is 410 cubes. A Scat crank, Scat rods, Probe pistons, Edelbrock heads, Edelbrock intake, factory adjustable rockers, you'll be under $10k and have a stout engine. The 3.980" Scat crank will get you the 410-416 cube range, the 4.125" crank will get you around 430 cubes, and the 4.250" crank will get you around 445. The last two use BBC rods and will save you a little money.

T&D's are nice, but factory adjustable (or even non-adjustable on a hydraulic roller) rockers will suffice in most street cases.

If you really need a budget engine, nothing wrong with a 390. A little overbore will get you close to 400 cubes, and again, would make for a strong engine.