I will say keep your cars and work through any issues with it, I have regreted trading off the 5.0 since. All cars have issues.
2014 Black 3.7 6M. 20 inch black bullets, Pypes Axle back, matte black super snake stripes, next up JLT intake.
2011 Mustang 5.0 Race Red. gone and was sick
2011 Mustang 3.7, gone sold 3 times since, that I know of.