Its really not. Lets be realistic, these are movie cars and production teams need to create driving/running vehicles within reason. They don't have to be pure movie spec, but they have to get the job done.
The only thing wrong, is that mopar can't/won't pump out SB crate motors within comparable pricing of the SBC's.
Its just unreasonable to have say 6 movie chargers and have 4-5k in rebuilding costs to get a good motor they can thrash(and no warranty, unlike those SBC's
