400BB Engine
The 400 is an excellent motor for a stroker build. Use a 440 crank - and instantly get 451 or 474 cubic inches. It's a little more costly due to machining the mains of a 440 crank to fit the 400 block and you would need special pistons (KB's are relatively cheap) $315 for the set, but if it's in the budget you could make some serious power.