The engine has been rather noisy and I finally took it to a reputable race shop to find out if it was a real issue or just a Ford Zetec They put her on the dyno and made 180 @ 7200 before it started to drop off but showed it was running very lean. They said the noise could be piston slap so they dumped the oil filter and the oil looks like silver paint. At that point the assumption was a main bearing was the issue and a rebuild was discussed or a new power plant, both = $$$$. So I left after being told to drive easy (After red lining her on a Dyno) and we can price rebuilt power plants vs a rebuild. On the drive back home 56 Miles at a steady 62mph I come to realize that the Dyno test was not the best thing to do.... (1/4 mile to go) bang and the engine sounds like a a tin can with a rock in it. My guess is a main bearing has gone so I assume the choice has been made and a new engine? The question is, the engine is a Ford racing Zetec 2.0 that had been bumped to a 11.1 compression Kent Rally cams, HC Cosworth forged pistons, oversize valves, race ported. and on with all this work done on the engine should I try to have it rebuilt? (did nurse her home so I may have caused even more damage) If I go for a reconditioned power plant (not a Ford Racing option) is it wise to reuse any salvageable HP parts from the old engine and use in a reconditioned unit? If I go for the engine swap can I drop a 2.3 Eco boost in place of the souped up 2.0? Will I get the same HP output? If I can go with a 2.3 Eco boost what issues will I face going from a Zetec 2.0 to a 2.3 Eco boost? A little broad but hopefully I can get some input as to my best option.