I have currently inside my 81 el camino a 400 small block..I have just discovered that the headers that i used..hooker shorty headers...dont really fit..on the passenger side one of the tubes is against the frame..Will the flow tech headers fit without any sort of modifications? A 400 small block shouldnt be bigger than a 350 or am i overlooking . I am also looking at perhaps putting in some ram horns as an alternative, they are the next best thing..ANyone with more input please feel free to give me some..I read the other posts but im still kinda leary of getting another set of headers unless i know they are gonna work out..Also .do i have to have a special crossmemeber to have true duals? Or is that something a good muffler shop can work around..
thanks again guys..

If you want headers that fit call the manufacturers and talk to them. They have loads of information and are completely willing to help you get the right part. Its good business for them and they do it all the time. I would think that any header that fits on a 350 inside an Elky or a 305 for that matter will also fit the 400 they are phisically the same size outside, its the Bore and Stroke that make it a 400.

thanks for the advice elky pete...i figured the blocks were the same size..But for a hot second i questioned myself on if i was right about that. thanks for setting me straight. I think i have found some that will fit..THey are the flowtechs..i just dont know if i should go with long or short..short looks like it will fit for sure..long ones im kinda leary. I have already ruined a 200 set of hookers that i thought might fit. even though it wasnt meant for that car. I didnt ruin them actually the mechanic did lol..What do you think i should go forward with .the longs or the shorties.

Well it depends on what you looking for in the way of power. Long header tubes will give you more on the low end torque and good upper end torque shorty header will give you a good upper end but lack a bit on the lower end.

Generally most people prefer the long tubes over the short ones. I have shorty on my 76 (DynoMax Cerma Coated) and long tubes on the 80, same brand. Different engines different expectations. The 76 has a 383 with loads of low end torque. The 80 has a 355 with a better upper end power range but way less torque, which is a function in my case of the stroke not the headers.

If you think about it, if your running the Elky on a track all your power needs to be between the lights. 1/8th or 1/4 times. So short headers are not necessarily going to hurt that. My 80 is more built for street and show so a more rounded power band is my preference there.

So basically you need to figure out where you want the power band and go from there.

i like the long tubes..But i put a set on my 84 vette along with a straight system and i found i lost low end power..i just want a nice around town daily driver..with a lil pop.