lsa is $11,199
http://paceperformance.com/i-6255521...te-engine.html
trinity 5.8 ~25-26k I have heard but there is not good source yet. the last gen 5.4 was $22-23k if I remeber right.
5.8 has forged pistons put PM forged rods 2.3L eaton@15psi. LSA has hypereutectic pistons and PM forged rods 1.9L eaton@8.5psi.
When I was looking at the GT500 one of the things tha gave me pause was the way the block is manufactured. it is punched way out and the cyliner wall have a special process perfomed on them.
Sounded like an issue with the block would require a new one. I have had mustangs before and you can make great power but they cost more $$$ for hp if you have an issue with the motor.