the easyist 1 is the puma 1.7 engine. the loom and ecu is just a straight swap, i just unplugs and the puma loom just mates up to the rest of the fiesta loom. and u can use the 1.25 zetec box on it

the 2ltr focus engine will be alot more hasle, will be diferent mounts, engine is the other way round and think the box is diff to. not worth the hasle for 5bhp.

i put the puma engine in my zs and is got 135bhp with just a 421 manifold and system. defo the eayist option