I think its possible to get a Ztec into the 14s with a turbo. I'm not sure about the Atx powered cars, but Ztec has alot of potential.
I was looking at the specs of the FR200 and it seems that they are making 300hp with a stock connecting rods and crank.
300hp will definately be a low 14 possibly high 13
Check out
http://www.fordracing.com/performanceparts/html/project-fr200.htm for more info...