Whats wrong with the z24?? I can show you some z24's runnin mid 14's... those 3.1 could be some old push rod tech engines, but if done right, they can eat up some 2.5's and 3L's on here, I'm currently dropping a 3400 SFI Mated to a 5 speed in my cavalier, wanna challenge?
go to www.v6z24.com look me up. I'll be gladly to take any 3L N/a Duratec around my area when my 3400 swap is complete
infact heres a nice video of a cavy z24 second generation, with a built up 3.1 (3100 SFI heads, intake, exhaust) running high 14's