yes, i have a th400 behind my 355 in my 74 camaro drag car. its only in there because it was fresh and i got a steal on it. yes it will pull a little more power but claiming a 30-40hp difference is just stupid.Chevyman85 said:Have you ever ran a TH-400 behind a small block? There is a reason why everyone doesn't run them besides the overall weight, they are stronger becuase they use heavier internal components and therefore have more resistance. They rob a considerable amount of power, and behind almost any small block they are nothing more than bragging rights.maliburacinfreak said:if you put a 400 in it, youll never kill it and that 30-40hp drain is just an insane figure. it wont take half of that. but for mileage reasons, id keep the 200r4