Hi all,
I'm working on a car, and I'm trying to decide on what headers it needs, both from a fitment and durability standpoint as well as what tube sizes would be best. Here's the deal: It's a 440 in a challenger that has a comp cams XE 274 hydraulic flat tappet cam, a performer rpm intake, a 750 holley vacuum secondary carb, and stock hi-po manifolds. Right now the car also has a stock 1970 big block exhaust system bolted up to those manifolds. By stock I mean it has date-coded mufflers, not just a system somewhat similar to factory issue.
I think that exhaust system is corking it up, considering what the cam an intake manifold are capable of. I think a set of headers with 1 3/4" primaries and 3" collectors would be right since this car is pretty much street only. Accordingly, I think a set of 3" pipes would allow it to breathe well. We're not looking to make power past about 6k with this combo, so unless you guys think otherwise, I would say 1 7/8" primaries would be too big.
Can you guys recommend a good header out of all the choices there seems to be?