I have a 78 CJ7,4.2 with the Howell EFI and I have talked a little about changing to the 4.0 head, what I need to know is what to get intake and exhaust from, I would like a header, but I have EGR on my jeep and I think I need to keep it for smog inspection here in California. Is there a more efficient intake exhaust combo that i can put on the 4.0 head that has EGR?