So many issues really. I was talking to my mechanic the other day about dropping the puma 1.7 in the fiesta, thinking it's not too much of a challenge lucky for me my mechanic is quite possibly the best in the uk. Massive job. If you want to do it you need a donor car. Gearbox change, ecu so much crap needs to be done. I genuinely thought it would be a case of swap the engine out and job done. Lol what a fool I was.
Ps he is that good: sent my friend to get a tyre changed and as he drove into the garage he told my mate his rear axle was bent. The engine was still running and he hadn't even got out of the car. He got a ruler out to show him. 1 cm wrong and he spotted it in sub 10sec.
On the subject of bottom end for a Zetec s mine is solid and might be for sale soon. Long story short went to another mechanic while mine was on holiday for some head work. He timed it wrong and broke all the exhaust valves. Head is ruined and will never pressurise as the valve ports were all smashed and broken around the edges. Off the road for at least another two weeks and if he can't get a head it will be a new engine.