Will a header made for a B16a fit a b20? The b16a has a shorter block right? So I'm guessing it won't fit a B20 or a B18 even... Anyone know for sure?

 

Yes it will but it will be closer to the oil pan....not by much but closer.

The bigger issue is the end of the header....the SI's have a shorter lenght than the GSR/LS's

 

hmm, i have heard it won't even clear the oil pan.... is this from personal experience or from first hand experience from a friend or something? I wanna be sure it'll clear the oil pan...

I dont' care about the length as I am putting on a new universal cat and need to get that welded on anyway (so length isn't a factor)...

Thanks in advance if anyone knows for sure...