the 2.1 ZVH NON turbo is a good engine. It's torquier than the 16v zetec too. For cheapness though, bang in a 2 litre zetec, put it on carbs, and u will have over 150hp, possibly 170.

For ultimate power, the turbo route obviously. A 1600CVH turbo is going to do 170 minimum, with massive tuning potential.