Well for sure parts are very expensive and can add up quick. You can buy some nice GEN 2 truck engines in the $2500 range but to use them in a 2014 GT, you will need new cams with new phasers. They are not cheap. Although the time chain kit is cheap then of course you need a front cover. All this can add another $2500. I guess with GEN 2 Mustang engines, you just need a new stock intake cam and both phasers. Co-Part has lots of GEN 1 engines with 100,000 mile plus on them for $4500. I guess the deal would be a low mile GEN2 Mustang engine for about $5000 which has $800 worth of Boss Exhaust Cams already in it. Just use Rockauto stock 2014 intake cams for $250 a set and new phasers for another $250 a set.