Originally Posted by
hambone
The 41021 is called a short curved header but it is actually .200" longer than the 41005 "[" shaped manifold that is referred to as a medium length, go figure. Those 2 work well, but the 41001 didn't, it's .100" shorter than the 41005, same shape.
Close enough for government work for sure
The 41021 has more volume than the 41029 but less than 41030
The different shapes of headers create different pulse wave escape/return effects , some work well with some pipes ,some work well with some engines and some you just don't wanna use
The exhaust length, shape and all that hoopla is a deeeeeeeeep conversation fershur , do some research
