Your best bet is to leave the header... it will flow better than the stock manifold, as stated above.
If you want to get rid of the aftermarket exhaust, join a Honda forum and see if anyone is willing to SWAP you exhaust for a stock setup from the model you need... I'll bet guys will jump at it... even up, with no money except shipping costs, I'll bet you could get them to pay shipping both ways.
__________________
Bow
|