Magnus manifold I've been told flow better than the 340 ones.
Important pretty sure my old 5th ave I had 4-5yrs ago got around 20mph. That was with leanburn delete and we pitched the cat and later had dual put on. Important thinking the headers and kit listed on the dippy forum will be the ticket as it'll cost more just to have a shop run the exhaust from headers back than it will for me to buy headers and kit and do it myself. Its under $400 for the setup. Shops charge that or more from the manifold back.
Its almost at a half tank now an has about 118 miles on the trip odometer. So mileage is looking better on her but want better