What size are 1.875 headers REALLY
Metal pipes/tubes are measured from the outside. Flexible hoses are measured from the inside.
You may give up some bottom end with that big of primary size. I used to run a 1 5/8 stepped to 1 3/4 and those things had insane midrange. I switched to a full 1 3/4 and top end power picked up from 4-5k and up but midrange felt weak and soggy in comparison.







