the 6.2 will hang in there right with the idi
the idi will perform better, so the winner is hands down the idi
im biased to ford, but i also checked around before i chose idi
lets give you an example of idi strength
my trucks motors had roughly 250k on it and was ticking good less some oil consumption from the previous owner not changing the oil, so ok one night it pops the head gaskets while im driving no big deal, ill just continue to add coolant
another night, a night when no one i know is up and i don't have the money for a wrecker to come get me, the sum beetch pops the upper radiator hose, im assuming from coolant system pressures rising from driving down the highway at 65+ mph, well i have 15 miles to go and im not stopping
one of our oil burner members heard the aftermath of that fiasco, i pegged every gauge on that cluster, and by the time i was down i was crawling up my exit ramp near my house, but i got it into the park in ride, locked the doors, paid my buddy 5 bucks to come get me after waking him up and went on my way. i came back about 2 weeks later, figuring it wouldn't started up, fired it right up drove it another 8 miles to my dealership with no coolant in it
i separated the cylinder head and the block so bad you can literally feel compression leaking from the back cylinder, and physically see it, might have been 1/4 of an inch gap
but ya, you really cant go wrong with either, but its hard to compare a motor making maybe 140hp vs a motor making probably 200-210hp
go with the turbo ford, and check your transmission main harness on the side of the trans. its put on there with a bolt, unbolt it, clean it, both sides, slam some dielectric grease in the connector, put it back on, and i think you can drive safely along your way