Pipe dream motor swap: What would you bolt into your A-Body?
I think I'd have to vote for the 5.2L flat plane crank Voodoo engine from the Shelby GT350 with a Tremec 6060, 4.10 final drive.
Yeah, I know...it's a Ferd but this is an insanely great engine and it fits my vision for a wild, high winding V8 with a screaming exhaust note that rewards high rpm shifts and keeping those revs sky-high all the time.
It pushes the 3800lb Mustang to low 12s, it ought to be mid 11s in the Dart (~600lbs lighter).