Header Question...

[Vteckidd]

I'm thinking about just modifying my DC 4-2-1, with longer primaries (I have no A/C, so the space is there) and then adding a megaphone and reverse cone. I'll be making the megaphone/reverse cone and just using 1 7/8" piping from the flange to the existing primaries. With the "stock" primaries flared to where the 1 7/8" pipe from the flange, will slide in, the transition shouldn't be choppy and pretty smooth.

Obviously, this it just until I can get a real header or at least a decent one, but I don't want to do random things that aren't at least good ideas... lol

What size are the primaries on the DC USDM? they should be close to 1 7/8th almost all B series headers nowadays are close to that or 1.75in etc bloh blahb blah

You would be surprised how much a 2.5in collector makes. Chop off the last 8in of your USDM header and weld in a 2.5in pipe like my Narrow header and youll see good gains.

[Catnip]

What size are the primaries on the DC USDM? they should be close to 1 7/8th almost all B series headers nowadays are close to that or 1.75in etc bloh blahb blah

You would be surprised how much a 2.5in collector makes. Chop off the last 8in of your USDM header and weld in a 2.5in pipe like my Narrow header and youll see good gains.

I think you're right on the size, although I haven't measured for sure. I already did the 2.5" collector mod, but I can see how it could be improved... especially if I'm going B20 bottom end.