not exactly apples to apples. 5.7's in cars and trucks are all through automatic transmissions and generally turning 20 inch wheels. 294 rear wheel horsepower is pretty decent for headers and a mod man intake. I would guess it made 260 or less rwtq.
Not true in the new challenger you can get a tremec 6 speed with a 5.7...
I've gotten my 2008 charger 5.7 (R/T) up to 135mph with a tune and exhaust
It's not possible to hit 500hp in a 5.7 without a stroker or forced induction
We retrofitted a 6.1 kenne bell supercharger running 8 psi on a 2010 Challenger 5.7 with long tubes and corsa exhaust as well as a custom tune (it was an auto) and got 412 hp to the wheels. We ended up taking it off because we bent a couple pushrods having too much fun. So I would say it is possible but not with out a thick wallet and someone who knows what they're doing
